Murakami SP 1400 Diazo Screen Printing Emulsion – Durable, High-Resolution Emulsion for Water-Based, Discharge, HSA & Plastisol Inks

Murakami

Murakami SP 1400 Diazo Screen Printing Emulsion - Durable, High-Resolution Emulsion for Water-Based, Discharge, HSA & Plastisol Inks

Murakami SP-1400 is a blue diazo emulsion engineered for textile production shops that prefer the traditional diazo workflow — longest unsensitized shelf life, easy reclaiming, and the familiar mix-the-sensitizer process. 42% solids for solid stencil build. Compatible with plastisol, discharge, and water-based textile inks (water-based requires Murakami hardener). Mix the included diazo packet at first use, let stand 2 hours minimum (preferably overnight), then coat, expose, and print like any standard scoop-coater emulsion. The economical workhorse for shops that don’t need the speed of PVA-SBQ photopolymer.

True Diazo Chemistry — Mix at First Use
Per Murakami TDS, SP-1400 ships with a diazo sensitizer packet to mix into the emulsion at first use. Once mixed, follow standard scoop-coater workflow. The diazo packet keeps the emulsion fresh on the shelf longer than pre-sensitized alternatives.
Longest Unsensitized Shelf Life
Per Murakami TDS, unsensitized SP-1400 emulsion has a shelf life of at least one year when stored at room temperature. Buy ahead, stock up — the diazo stays separate until you’re ready to use the emulsion.
42% Solids for Solid Stencil Build
Per Murakami TDS, 42% solids build a durable stencil with one or two coats each side. Same solids content as Aquasol HV (the PVA-SBQ workhorse), making SP-1400 the traditional diazo equivalent.
Multi-Ink Compatibility
Per Murakami TDS — compatible with plastisol, discharge, and water-based textile inks. Plastisol ready after sensitizing; water-based and discharge require Murakami hardener for water resistance.
Virtually Pin-Hole & Fish-Eye Free
Per Murakami TDS — the formulation is engineered to minimize surface defects that cause production rejects.
Extremely Durable On Press
Per Murakami TDS — SP-1400 produces a tough stencil that holds up to long production runs without breakdown.
Same-day shipping · In stock at our San Antonio, TX warehouse · FREE shipping on orders over $200 · Order by 3:30 PM CT

Price range: $24.99 through $2,003.75

SKU: Mur SP-1400 Category: Tags: , , , , , , , , ,

Description

Murakami SP-1400 Emulsion

The Traditional Diazo Emulsion for Textile Production

Murakami SP-1400 is a blue diazo emulsion engineered for textile production shops that prefer the traditional diazo workflow — longest unsensitized shelf life, easy reclaiming, and the familiar mix-the-sensitizer process. 42% solids for solid stencil build. Compatible with plastisol, discharge, and water-based textile inks (water-based requires Murakami hardener). Mix the included diazo packet at first use, let stand 2 hours minimum (preferably overnight), then coat, expose, and print like any standard scoop-coater emulsion. The economical workhorse for shops that don’t need the speed of PVA-SBQ photopolymer.

Diazo
42% solids, blue color
Diazo packet included — mix at first use

Key Features & Benefits

True Diazo Chemistry — Mix at First Use
Per Murakami TDS, SP-1400 ships with a diazo sensitizer packet to mix into the emulsion at first use. Once mixed, follow standard scoop-coater workflow. The diazo packet keeps the emulsion fresh on the shelf longer than pre-sensitized alternatives.
Longest Unsensitized Shelf Life
Per Murakami TDS, unsensitized SP-1400 emulsion has a shelf life of at least one year when stored at room temperature. Buy ahead, stock up — the diazo stays separate until you’re ready to use the emulsion.
42% Solids for Solid Stencil Build
Per Murakami TDS, 42% solids build a durable stencil with one or two coats each side. Same solids content as Aquasol HV (the PVA-SBQ workhorse), making SP-1400 the traditional diazo equivalent.
Multi-Ink Compatibility
Per Murakami TDS — compatible with plastisol, discharge, and water-based textile inks. Plastisol ready after sensitizing; water-based and discharge require Murakami hardener for water resistance.
Virtually Pin-Hole & Fish-Eye Free
Per Murakami TDS — the formulation is engineered to minimize surface defects that cause production rejects.
Extremely Durable On Press
Per Murakami TDS — SP-1400 produces a tough stencil that holds up to long production runs without breakdown.
Outstanding Resolution, Easy Reclaim
Per Murakami TDS — outstanding resolution and definition properties combined with easy reclaim. Diazo emulsions historically strip cleanly with standard reclaiming chemistry, making SP-1400 a favorite of shops that reclaim screens frequently.
Blue Color for Stencil Visibility
The classic Murakami blue emulsion color most printers are used to. Easy to see uneven coating, registration marks, and reclaim residue.

What Is a Diazo Emulsion?

Screen printing emulsions come in three main chemistry types: diazo (requires mixing a sensitizer powder at first use, longest unsensitized shelf life), photopolymer / PVA-SBQ (pre-sensitized, faster exposure), and dual-cure (combines both chemistries). Murakami SP-1400 is a true diazo emulsion — the traditional, time-tested screen-printing chemistry.

Diazo emulsions ship unsensitized with a separate packet of diazo sensitizer included in the box. You mix the diazo packet into the emulsion at first use (one-time step), then coat, expose, and print as normal. Once sensitized, the emulsion is light-sensitive and needs to be used within 2-3 weeks for best results.

Why choose diazo over pre-sensitized PVA-SBQ?
Three reasons. One: diazo emulsions have the longest unsensitized shelf life — up to a year in storage, so you can keep stock on hand without worrying about it going stale. Two: diazo chemistry reclaims easily and cleanly, which matters for shops that reclaim screens frequently. Three: some printers and shops simply prefer the traditional diazo workflow they’ve used for decades. The trade-off vs PVA-SBQ: diazo exposures are significantly longer (per Murakami’s TDS, roughly 3-5× the exposure time of equivalent SBQ emulsions) and the sensitized pot life is limited to a few weeks.

The Full Murakami Emulsion Lineup at River City Supply

Murakami makes ten different emulsions for different screen-printing needs. Murakami SP-1400 is one option in the lineup — but other Murakami emulsions may fit specific workflows better. Use this chart to compare:

EmulsionTypeColorSolidsInk CompatibilitySensitizingBest For
Photocure ProDual-cure (diazo + photopolymer)Blue38%Water-based, discharge, plastisol, solvent, UVDiazo packet included — mix at first useVersatility — one emulsion for every ink type
Photocure BLUPVA-SBQ pure photopolymerBlue41%Plastisol, discharge, water-based textilePre-sensitized — ready to useMulti-ink production, blue color preference
Photocure SRPVA-SBQ pure photopolymer (solvent-resistant)Magenta37%UV, solvent, textile (plastisol); also backs capillary filmsPre-sensitized — ready to useSolvent/UV ink work + capillary film backing
T9 PinkPVA-SBQ pure photopolymerPink44%Water-based, discharge, HSA, plastisolPre-sensitized — ready to useMulti-ink, 44% solids, 17,000 mPa·s viscosity
T9 VioletPVA-SBQ pure photopolymerViolet44%Water-based, discharge, HSA, plastisolPre-sensitized — ready to useSame as T9 Pink, violet color preference
TXRPVA-SBQ pure photopolymerPink41%Water-based, discharge, HSA, plastisolPre-sensitized — ready to useVersatility, fast exposure, fine detail
Aquasol HVPVA-SBQ pure photopolymer (high-viscosity)Blue42%Water-based, discharge, plastisolPre-sensitized — ready to useThick stencils, heavy ink deposit, fast exposure
Aquasol HVP PinkPVA-SBQ pure photopolymer (high-viscosity)Pink42%Water-based, discharge, plastisolPre-sensitized — ready to useThick stencils, pink color preference
Aquasol HS3SBQ-Type one-pot (water-resistant)Blue49%Water-based, discharge, plastisolPre-sensitized — ready to useHighest solids (49%), thick high-EOM water-based prints
★ This Product
SP 1400		DiazoBlue42%Plastisol, discharge, HSA, water-based textileDiazo packet — mix at first useTraditional diazo workflow, long stencil life, easy reclaim
Not sure which Murakami emulsion is right for you?
Call (512) 454-0505 and tell us what inks you’re running, your typical print run length, and whether you want pre-sensitized convenience or diazo flexibility. We’ll match you to the right emulsion for your shop’s workflow — not just sell you the most expensive option.

What Murakami SP-1400 Is Used For

Murakami SP-1400 is engineered for shops where pre-sensitized convenience, fast exposure, and reliable multi-ink performance matter. If you’re in one of these categories, this is the right choice:

Shops With Traditional Diazo Workflow
If your shop has been using diazo emulsions for years and the workflow is dialed in, SP-1400 fits without changing anything. The mix-the-sensitizer step is the same routine you already know.
Long-Term Inventory Stocking
Per Murakami TDS, unsensitized SP-1400 lasts at least 1 year on the shelf. Shops that buy in volume and don’t burn through emulsion quickly benefit from the extended shelf life vs pre-sensitized PVA-SBQ (which doesn’t have the diazo on a clock but uses the SBQ shelf life).
Plastisol Production With Frequent Reclaim
Per Murakami TDS — SP-1400 reclaims easily. Shops that reclaim and reuse screens frequently appreciate the clean stripping that diazo emulsions offer vs harder-stripping dual-cure formulations.
Water-Based Textile Printing (With Hardener)
SP-1400 handles water-based textile inks when hardened with Murakami MS Hardener or Hardener A&B. For shops doing water-based prints, the hardener is essential for extended-run durability.
Discharge Ink Printing
Discharge inks are aggressive on emulsion. SP-1400 handles discharge work, with Murakami hardener applied for the required durability.
Beginner Print Shops Learning the Craft
Diazo is the chemistry many textbooks and instructors teach with. SP-1400 is the textbook diazo emulsion — learn here, then expand to PVA-SBQ or dual-cure when you understand the underlying workflow.
Economy-Focused Production
Diazo emulsions are typically more cost-effective per quart/gallon than PVA-SBQ. SP-1400 is the economical workhorse for shops where unit cost matters more than exposure speed.

How to Mix the Diazo Sensitizer (First-Time Use)

Murakami SP-1400 ships unsensitized with a packet of diazo sensitizer included in the box. The diazo is kept separate because it has a shorter shelf life once mixed into the emulsion. Mixing is a one-time step performed when you open a new container — after that, the sensitized emulsion is ready for normal scoop-coater application.

⚠ Sensitized shelf life is limited: Per Murakami’s TDS, sensitized Murakami SP-1400 should be used within 2-3 weeks for best results at room temperature. Refrigeration at ~40°F adds usable life. If your shop uses Murakami SP-1400 slowly, keep the unsensitized container on the shelf and only mix what you’ll use in 2-3 weeks.
1
Mix the Diazo Sensitizer
Per Murakami TDS — mix the sensitizer according to the instructions on the bottle. Open the diazo packet, add the specified amount of room-temperature distilled water, cap and shake until fully dissolved (cloudy/yellow with no visible particles).
2
Pour the Diazo Solution Into the Emulsion
Per Murakami TDS — pour the entire diazo solution into the emulsion container and mix thoroughly. Work under yellow safelights once the diazo is added — the emulsion becomes fully light-sensitive at this point.
3
Let Bubbles Settle (2 Hours Minimum, Preferably Overnight)
Per Murakami TDS — to reduce air bubbles, let the emulsion stand for two hours (preferably overnight) before using. Coating immediately after stirring traps bubbles in the stencil and causes pinholes. The wait is worth it.
4
Label the Container With Mix Date
Write the date sensitized on the container with a permanent marker. Per Murakami’s TDS: use sensitized Murakami SP-1400 within 2-3 weeks for best results. Refrigeration extends usable life. Knowing the date prevents using stale emulsion.

Step-by-Step: Coating & Exposing Murakami SP-1400

Murakami SP-1400 ships unsensitized with a diazo packet that you mix once at first use (see section above). Once sensitized, the emulsion coats, exposes, develops, and prints like any standard scoop-coater emulsion.

1
Degrease the Mesh
Apply mesh degreaser to both sides of the screen and work into a lather with a soft brush. Rinse thoroughly with clean water and allow the screen to dry completely before coating. Murakami 801 Screen Degreaser is the recommended chemistry per the TDS. A properly degreased mesh is the foundation of every successful stencil.
2
Set Up Your Coating Station Under Yellow Safelight
Per Murakami TDS — work under yellow safelights. Avoid exposure to sunlight, fluorescent, and incandescent lights. Set the screen on a stable surface at a slight upward angle.
3
Coat the Print Side
Per Murakami TDS — use a clean dry coating trough that has a nick-free surface for smooth coating. Pour an ample amount of Murakami SP-1400 into the scoop coater. Apply one or two coats of emulsion to the print side. Aim for full uniform coverage with no streaks, gaps, or visible mesh through the emulsion.
4
Flip Screen, Coat the Squeegee Side
Per Murakami TDS — rotate the frame 180 degrees and apply one or two coats of emulsion to the squeegee side. Additional coats may be added to the print side if thicker stencils are required.
5
Dry Flat With Print Side Down
Per Murakami TDS — dry the coated screen horizontally with the print side DOWN in a clean light-safe area. Target 86-104°F (30-40°C) ideal and 30-50% relative humidity with good air circulation. A screen drying cabinet with heated airflow holds these conditions reliably.
6
Position Your Film Positive
Place the film positive on the PRINT SIDE of the screen with the emulsion side of the positive in direct contact with the emulsion. Lock down with vacuum (preferred) or weighted glass — no air gaps, no light leaks. Per Murakami TDS, clean the film positives and vacuum frame glass prior to exposure to minimize pinholes.
7
Expose to UV Light
Expose using a metal halide or LED UV exposure unit. Per Murakami TDS, exposure is affected by mesh color, emulsion type, coating thickness, lamp type, and bulb age — see the Technical Specs tab for the TDS exposure data table as a starting point. Run a 21-step Stouffer wedge test on your first screen to dial in your shop’s optimal time.
8
Wash Out the Stencil
Per Murakami TDS — gently spray both sides of the screen with lukewarm water, wait a few seconds to allow emulsion to soften, then wash the print side of the screen until the image is fully open. Rinse both sides thoroughly. Don’t use high-pressure water — it can damage fine detail.
9
Dry the Developed Screen
Allow the developed screen to dry completely before printing. A fan or warm drying cabinet (under 104°F / 40°C) speeds drying. Once dry, you can spot-touch any small pinholes with blockout — Murakami 901 Blockout Red is ideal for this. The screen is now ready for press.

Having an Emulsion Problem? Free Troubleshooting Guide

Every screen-printer runs into emulsion problems eventually — pinholes, washout failures, sawtooth edges, fish eyes, stencils breaking down mid-run. We’ve put together a comprehensive troubleshooting guide organized by symptom so you can find your issue fast and get back to printing.

River City Supply Free Resource
The Complete Screen Printing Emulsion Troubleshooting Guide
19 specific emulsion issues across 5 workflow stages (coating, exposure, washout, on-press, reclaim). Quick diagnostic table at top so you can triage fast. Prevention checklist so you stop the problem from coming back.

View Troubleshooting Guide →

8 Pro Tips for Murakami SP-1400

Distilled from Murakami’s TDS, professional shop experience, and our customer feedback. Save yourself the trial and error:

1
Mix the Diazo Packet Per Bottle Instructions
Per Murakami TDS — mix the sensitizer according to the instructions on the bottle. Pour the entire solution into the emulsion and mix thoroughly. Work under yellow safelights once the diazo is added.
2
Let Stand 2 Hours, Preferably Overnight
Per Murakami TDS — to reduce air bubbles, let the sensitized emulsion stand for two hours (preferably overnight) before using. This is the diazo step that PVA-SBQ users find unusual; it’s worth the wait to prevent pinholes.
3
Label the Container With Mix Date
Sensitized SP-1400 has a 2-3 week pot life at room temperature per Murakami TDS. Always write the mix date on the container so you know when to throw out an old batch.
4
Refrigerate to Extend Sensitized Pot Life
If your shop uses SP-1400 slowly, store sensitized emulsion in a dedicated refrigerator at ~40°F to extend usable life beyond the room-temperature 2-3 week window.
5
Diazo Exposes Slower Than PVA-SBQ
Per Murakami TDS — SP-1400 exposure times are significantly longer than PVA-SBQ emulsions (150-175 sec for mesh 86 vs 50-60 sec for PVA-SBQ Aquasol HV at the same mesh). Make sure your exposure unit can run long enough cycles.
6
Run a Stouffer Wedge Test on First Use
Per Murakami TDS, exposure is affected by mesh color, emulsion type, coating thickness, lamp type, and bulb age. The TDS exposure data is a starting point; a 21-step Stouffer wedge dials in your specific shop.
7
Use Hardener for Water-Based & Discharge Runs
Per Murakami TDS, SP-1400 is suitable for water-based and discharge inks when hardened with Murakami MS Hardener or Hardener A&B. Skip the hardener and the stencil breaks down on long runs.
8
Mix Smaller Portions if Throughput Is Low
If your shop uses SP-1400 slowly, keep an unsensitized 5-gallon bucket on the shelf and only mix smaller (quart-sized) portions at a time. This extends total usable emulsion life and reduces waste.

Pair Murakami SP-1400 With Murakami MS Hardener for Extended Runs

For water-based and discharge work running over a few hundred impressions, the stencil will gradually break down as the aqueous ink chemistry attacks the emulsion. Murakami MS Hardener is a post-exposure treatment that dramatically extends stencil life by cross-linking the cured emulsion for greater water, solvent, and abrasion resistance.

★ Murakami MS Emulsion Reclaimable Hardener

Applied after exposure, development, and blockout using a scoop coater on both sides. Cured in direct sunlight or a 100°F hot box. Compatible with diazo, dual-cure, and SBQ photopolymer emulsions across all major brands — so it works with Murakami SP-1400 and every other Murakami emulsion.

Key benefit: Unlike permanent hardeners, MS Hardener is RECLAIMABLE when proper procedures are followed — meaning you don’t lose your screen inventory to the treatment. Ideal for water-based, discharge, and aggressive plastisol printing.

View MS Hardener →

Note on Hardener A&B: Murakami also sells a two-part Hardener A&B for maximum durability. Per the Murakami TDS, stencils treated with Hardener A&B will NOT be reclaimable. View Hardener A&B →

Storage & Shelf Life

Unsensitized Murakami SP-1400
  • At least 1 year at room temperature (per Murakami TDS).
  • Store in original container, lid tight
  • Cool, dry, UV-light-safe area
  • Avoid temperature swings
Coated Screens
  • Up to 1 month at 59-77°F (15-25°C), 30-50% relative humidity, in total darkness
  • Total darkness required — no light leaks
  • Cool, dry environment
  • Stack with frames separated
Working Conditions
  • Yellow safelight (per Murakami TDS)
  • AVOID sunlight, fluorescent, incandescent
  • Drying temp: 86-104°F (30-40°C) ideal
  • Humidity: 30-50% relative humidity

Other Murakami Emulsions & Accessories

If Murakami SP-1400 isn’t quite the right fit, here are the other Murakami emulsions we stock — plus the accessories that pair with the Murakami SP-1400 workflow:

Murakami Photocure Pro

Dual-cure flagship. Diazo + photopolymer chemistry, 38% solids, blue. Compatible with water-based, discharge, plastisol, solvent, and UV inks. Diazo packet included.

View product →

Murakami Photocure BLU

Blue PVA-SBQ pure photopolymer at 41% solids. Pre-sensitized, fast exposure, multi-ink (plastisol, discharge, water-based textile with hardener). The textile production workhorse.

View product →

Murakami T9 Pink

Pre-sensitized SBQ photopolymer — no diazo mixing required. Fast exposure (3-5× faster than diazo), pink color for visibility, multi-ink compatibility.

View product →

Murakami T9 Violet

Same chemistry as T9 Pink, violet color. Some printers prefer violet visibility under their specific safelight conditions.

View product →

Murakami TXR Pink

Pre-sensitized PVA-SBQ photopolymer with 41% solids. Fast exposure, fine detail capability, multi-ink compatibility.

View product →

Murakami Aquasol HV

High-viscosity SBQ photopolymer for thicker stencil builds. Blue color, fast exposure. For shops needing heavier ink deposit.

View product →

Murakami Aquasol HVP Pink

High-viscosity SBQ in pink. Same advantages as Aquasol HV with the pink color preference. 42% solids for very heavy stencil builds.

View product →

Murakami Aquasol HS3

SBQ one-pot emulsion specifically engineered for thick EOM (high emulsion over mesh) prints. Water-resistant out of the can.

View product →

Murakami Photocure SR

Solvent/UV/plastisol photopolymer emulsion. For specialty solvent ink work and UV-curable inks that need an emulsion engineered for those chemistries.

View product →

Murakami MS Hardener

Post-exposure stencil hardener. Works with all Murakami emulsions. Reclaimable when proper procedures are followed. For extended water-based and discharge runs.

View product →

Murakami 901 Blockout Red

Fast-drying screen blockout for masking. Red color for visibility against blue stencils. Essential for touching up pinholes and masking off frame edges.

View product →

FREE SHIPPING ON ORDERS OVER $200
In stock at our San Antonio, TX warehouse

Orders placed before 3:30 PM CT ship same business day. Most US destinations receive in 2-5 business days. Need help choosing the right emulsion or troubleshooting an existing stencil? Call us — we’ve helped hundreds of shops dial in their screen-making process.

Call (512) 454-0505

Technical Specifications

Product Identification

SpecificationValue
Product NameMurakami SP-1400 Emulsion
SKUMUR SP-1400
ManufacturerMurakami Screen USA
CategoryDirect screen printing emulsion (Diazo)
Chemistry TypeDiazo (sensitizer mixed at first use)
ColorBlue
Shipping OriginSame-day from RCS San Antonio, TX (orders by 3:30 PM CT)

Physical Specifications

PropertyValue
Solids Content42% (per Murakami TDS)
ViscosityStandard diazo viscosity — coats smoothly with standard scoop coater technique
SensitizingDiazo packet included — mix at first use
Exposure Speed3-5× faster than diazo emulsions (per Murakami TDS)
Surface QualityVirtually pin-hole and fish-eye free (per Murakami TDS)
Hardener CompatibilityCompatible with Murakami MS Hardener (reclaimable) and Hardener A&B (non-reclaimable)

Ink Compatibility

Ink TypeCompatibility & Notes
Plastisol★ Excellent — ready to use, no special considerations.
Discharge★ Compatible — pair with Murakami MS Hardener for runs over 200 impressions.
Water-based textile (with hardener)★ Compatible — pair with Murakami MS Hardener for runs over 200 impressions.

Exposure Data (Per Murakami TDS)

Light source for these times: 5kW Metal Halide lamp at 40″ distance

Mesh / ColorEOMExposure Time
Mesh 86 (White)—150-175 sec
Mesh 110 (White)—120-150 sec
Mesh 200 (Yellow)—90-120 sec
Mesh 300 (Yellow)—60-75 sec
Mesh 350 (Yellow)—30-50 sec

Note: Per Murakami TDS — exposure is affected by mesh color, emulsion type, coating thickness, lamp type, and bulb age. Use these times as a starting point. Run a 21-step Stouffer wedge test on your first screen to dial in your shop’s optimal exposure.

Available Sizes

SizeBest For
QuartFirst-time users testing Murakami SP-1400; very low-volume shops
1 GallonSmall/hobby shops, casual users, monthly emulsion turnover
5 Gallons★ Most popular — production shops, weekly screen-making cycles
50 GallonsHigh-volume production facilities, contract printers, multi-line shops

Shelf Life Summary

ConditionShelf Life
Emulsion (sealed, room temp)At least 1 year at room temperature (per Murakami TDS).
Coated screens (unexposed)Up to 1 month at 59-77°F (15-25°C), 30-50% relative humidity, in total darkness
Coated screens (exposed)Indefinite — exposed/cured stencils are stable

Technical Sheets / Safety Data Sheets / Documents

Official manufacturer documentation for Murakami SP-1400 Emulsion. Both documents open in a new tab.

SP-1400 Technical Data Sheet

Murakami’s official TDS for SP-1400. Includes diazo mixing instructions, exposure data for multiple mesh counts (86-350 using 5kW Metal Halide at 40″), 42% solids specification, hardener compatibility notes, and recommended workflow. Available on Murakami’s TDS hub.

View TDS on Murakami Screen USA →

SP-1400 Safety Data Sheet

SDS available on request through Murakami Screen USA. Covers chemistry composition (including diazo sensitizer), hazard identification, handling, storage, first aid, exposure controls, and disposal.

Request SDS from Murakami Screen USA →

For additional product information, technical bulletins, and the full Murakami emulsion catalog, visit Murakami Screen USA → · Have a question about specifications or application? Call us at (512) 454-0505.

FREQUENTLY ASKED QUESTIONS

Frequently Asked Questions

What does “diazo emulsion” mean for Murakami SP-1400?
Diazo means the light-sensitive component is a diazo sensitizer that ships separately from the emulsion base. You mix the diazo packet into the emulsion at first use (one-time step), let it stand 2 hours minimum (preferably overnight), then coat, expose, and print as normal. Compare to pre-sensitized PVA-SBQ emulsions like Photocure BLU or T9 that come ready-to-use with no mixing step.
Why is Murakami SP-1400 diazo instead of pre-sensitized PVA-SBQ?
Three reasons shops choose traditional diazo: (1) longest unsensitized shelf life — up to a year in storage, so you can stock without worrying about it going stale; (2) easy clean reclaiming — diazo emulsions strip cleanly with standard chemistry; (3) the familiar diazo workflow many shops have used for decades. The trade-off vs PVA-SBQ: diazo exposure times are 3-5× longer per the TDS, and sensitized pot life is limited to 2-3 weeks.
How does Murakami SP-1400 compare to pre-sensitized PVA-SBQ emulsions?
See the comparison chart in the Description tab. Quick version: Murakami SP-1400 is traditional diazo (mix sensitizer at first use, longer unsensitized shelf life, longer exposure times, easy reclaim). Pre-sensitized PVA-SBQ emulsions like Photocure BLU, T9 Pink, and Aquasol HV are ready-to-use with 3-5× faster exposure but shorter overall shelf life on the shelf. Pick diazo for traditional workflow + long shelf life; pick PVA-SBQ for production throughput.
How long does mixed (sensitized) Murakami SP-1400 last?
Per Murakami’s TDS, use sensitized Murakami SP-1400 within 2-3 weeks for best results at room temperature. Refrigeration at ~40°F extends usable life by several weeks. Many shops successfully extend room-temp use to ~4-6 weeks with some image-quality degradation. Always label the container with the mix date. If your shop uses Murakami SP-1400 slowly, keep an unsensitized 5-gallon bucket on the shelf and only mix smaller portions as needed — this extends total usable emulsion life and reduces waste.
Do I need to use a hardener with Murakami SP-1400?
Not always. Per Murakami’s TDS, Murakami SP-1400 is suitable for water-based and discharge inks WHEN HARDENED with Murakami MS Hardener or Hardener A&B. Without hardener, water-based and discharge ink chemistry will eventually break the stencil down on extended runs. For plastisol runs of any length, no hardener is required. For short water-based or discharge runs (under ~200 impressions), you may not need it. For extended water-based or discharge runs, the hardener is essential. View MS Hardener →
What’s the difference between MS Hardener and Hardener A&B?
Both are Murakami stencil hardeners that add water and solvent resistance. MS Hardener is single-part, applied with a scoop coater, and is RECLAIMABLE when proper procedures are followed — meaning you can still strip the stencil after using it. Hardener A&B is a two-part system that delivers maximum durability but is NOT reclaimable per Murakami’s TDS. Choose MS for screens you want to reclaim and reuse; choose A&B for screens you’re planning to retire or for single-use applications. MS Hardener · Hardener A&B
How long does Murakami SP-1400 last in storage?
Unsensitized emulsion has a shelf life of at least 1 year at room temperature (per murakami tds).. Coated unexposed screens last up to one month at 59-77°F (15-25°C), 30-50% relative humidity, in total darkness. Exposed (cured) stencils are stable indefinitely. Sensitized Murakami SP-1400 should be used within 2-3 weeks at room temperature per Murakami’s TDS — refrigeration extends usable life.
How thick should my stencil be?
For most textile work, one coat each side of Murakami SP-1400 is sufficient. Per Murakami’s TDS, additional coats may be added to the print side or squeegee side if thicker stencils are required. For very high deposit work (puff plastisol, glitter ink, foil base), consider building up the squeegee side with multiple wet-on-wet coats, or use Chromaline Super PHAT capillary film bonded with Murakami SP-1400 for 100-700µm stencil thickness.
What’s the right drying temperature and humidity?
Per Murakami’s TDS, target 86-104°F (30-40°C) ideal drying temperature at 30-50% relative humidity relative humidity, with good air circulation. A screen drying cabinet with heated airflow holds these conditions reliably. Drying temperatures over 104°F (40°C) can pre-cure the emulsion and cause exposure problems.
How do I reclaim a screen after using Murakami SP-1400?
Per Murakami’s TDS — (1) use Murakami 501, 505, or 507 Screen Cleaner to remove all excess ink from the frame; (2) remove the emulsion with Murakami 601, 605, or a solution of Strip Super-P; (3) rinse thoroughly; (4) use Murakami 701 to remove haze and ghost if required; (5) degrease with Murakami 801, rinse both sides thoroughly, and let dry. View screen cleaning chemicals →
What if my stencil washes out during exposure?
Most common cause: underexposure. Per Murakami’s TDS, exposure depends on mesh color, emulsion type, coating thickness, lamp type, and bulb age. Run a Stouffer wedge test to dial in correct exposure time for your specific shop. Other possible causes: emulsion that’s too thin (add more coats), light source too weak (consider upgrading to metal halide or LED), screen positioned too far from exposure source, or contaminated mesh (re-degrease and recoat). The Emulsion Troubleshooting Guide covers each scenario in detail.
What exposure unit do I need?
Per Murakami’s TDS, exposure data is provided for 5kw metal halide lamp at 40″ distance. LED UV exposure units can also work but typically need longer exposure times than metal halide for diazo emulsions. Standard fluorescent exposure units can work but require longer exposure times. The exposure data in the Technical Specs tab is a starting point; a 21-step Stouffer wedge test takes 5 minutes and dials in your specific exposure unit accurately.
Why is the emulsion blue?
The blue color makes the stencil visible during coating (so you can see uneven coverage and fix it), during exposure registration (so you can align film positives accurately), and during reclaim (so you can see when the stencil is fully removed). Pure-clear or near-clear emulsions are harder to work with for these reasons. Murakami offers emulsions in blue, pink, violet, and magenta depending on the formulation.
Can I use this emulsion for water-based printing without a hardener?
Yes for short runs (under ~200 impressions) and for single-job use. Per Murakami’s TDS, Murakami SP-1400 is suitable for water-based and discharge inks when hardened with Murakami Hardener and/or Hardener A&B for extended-run durability. Skip the hardener and the stencil chemistry will gradually break down as the aqueous ink attacks the emulsion. The decision is run length: short runs don’t need it, long runs benefit dramatically from it.
Is shipping really same-day?
Yes — Murakami SP-1400 ships from RCS’s San Antonio, TX warehouse. Orders placed before 3:30 PM Central Time on a business day typically ship the same day. Most US destinations receive shipment in 2-5 business days via standard ground. FREE shipping on orders over $200. Need it faster? Call us at (512) 454-0505 for expedited shipping options.
Questions Before Ordering?

Call us — we’ll help you pick the right Murakami emulsion for your inks and workflow. RCS has supplied screen printers since 2008. We use Murakami emulsions ourselves and can talk through specific issues.

(512) 454-0505

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