Matsui PrintGen Retarder MG | Anti-Drying Additive to Extend Open Time for Water-Based Screen Printing Ink

Matsui PrintGen Retarder MG – Keep Your Screens Open, Your Ink Flowing, and Your Production Moving.

Every water-based screen printer has experienced it: you step away from the press for two minutes to load a shirt, and the ink has already started drying in the screen. Image areas clog. Fine detail disappears. You stop production, wash the screen, and start over. On a 200-piece run, those interruptions add up fast.

Matsui PrintGen Retarder MG is the additive that prevents that problem before it starts. By slowing the evaporation rate of water from the ink system, Retarder MG keeps your ink wet and workable in the screen for significantly longer – giving you more time between strokes, cleaner open mesh, and fewer production stoppages. It is the single most important additive for any shop printing water-based inks in challenging conditions.

Unlike spraying water on the screen (which dilutes your ink and can cause bleeding) or simply flooding and hoping for the best, Retarder MG works from inside the ink itself. It becomes part of the ink formulation, providing consistent, predictable anti-drying performance from the first print to the last.

How Matsui PrintGen Retarder MG Works:

Retarder MG is a propylene glycol-based humectant – a substance that attracts and retains moisture. When blended into water-based screen printing ink, propylene glycol slows the rate at which water evaporates from the ink film sitting in the mesh openings. This keeps the ink in a fluid, printable state for a longer period, even when environmental conditions (low humidity, airflow from fans or ventilation, high temperatures) would normally cause rapid drying.

The result is extended “open time” – the window during which ink remains workable in the screen before it begins to thicken and clog. For printers working through fine mesh counts (230 and higher), where mesh openings are extremely small and ink films are thin, even a few extra minutes of open time can mean the difference between a clean run and a ruined screen.

At higher concentrations, Retarder MG also functions as a mild viscosity reducer, loosening the ink slightly for easier flow through the mesh. This dual function – anti-drying plus viscosity reduction – makes it one of the most versatile additives in the Matsui system.

Matsui PrintGen Retarder MG Key Features:

• Extends Screen Open Time: Slows ink drying in the mesh, giving you significantly more working time between print strokes. Keeps image areas clean and open throughout production.
• Prevents Mesh Clogging: Stops ink from thickening and blocking mesh openings – the number one cause of lost detail, ghosting, and production stoppages in water-based printing.
• Propylene Glycol-Based Formula: Uses a proven, non-toxic humectant that is widely used in food, pharmaceutical, and cosmetic applications. Safe to handle and environmentally responsible.
• Adjustable Usage Rate (1-5%): Fine-tune open time to match your exact conditions. Use 1-2% for mild retarding in moderate humidity, or 3-5% for aggressive anti-drying in arid climates and dry shop environments.
• Works as a Mild Viscosity Reducer: At higher concentrations, Retarder MG slightly thins the ink, improving flow through fine mesh and making the ink easier to print without adding water (which dilutes binders and reduces wash fastness).
• Critical for Fine Mesh Printing: Fine screens (230 mesh and above) have smaller openings where ink films are extremely thin and dry rapidly. Retarder MG is essential for maintaining open time on these high-detail screens.
• No Pot Life Limitation: Retarder MG does not start a chemical reaction. Mixed ink can be stored and reused on your normal production schedule.
• Universal Matsui Compatibility: Works with every Matsui water-based ink system – 301 Series bases, Neo Pigments, EasyPrint, Alpha Series, Infinity Colors, Discharge Bases, White Bases, and specialty inks.
• PVC-Free and Eco-Safe: Part of Matsui’s OEKO-TEX Standard 100 certified, CPSIA and HR4040 compliant additive lineup. Meets restricted substance lists (RSL) of all major apparel brands.
• Easy Cleanup: Water and mild soap. No solvents required.

Why Screen Printers Use Matsui PrintGen Retarder MG

Water-based ink dries by evaporation. That is what makes it eco-friendly and easy to clean up – but it is also what makes it difficult to print. The moment ink hits the screen mesh, water begins evaporating. In low-humidity environments, near fans or ventilation systems, or during warm weather, that evaporation accelerates dramatically. The ink thickens, clogs the mesh openings, and your image quality degrades.

This is not a problem you can solve by printing faster. Even experienced automatic press operators running at production speed encounter drying issues on fine mesh screens, multi-color jobs with long flash cycles, or in shops where climate control is limited. Manual press operators face it even more acutely – the time between pulling a squeegee stroke and loading the next shirt is often enough for ink to start drying in the image area.

Retarder MG solves this at the ink chemistry level. By modifying the ink’s evaporation rate before you ever put it on the screen, you eliminate the root cause of drying problems rather than treating the symptoms.

Shops that benefit most from Retarder MG include:

• Shops in arid or low-humidity climates (desert Southwest, high altitude, winter heating)
• Shops without dedicated climate control or humidification systems
• Manual press operators who need extra time between strokes
• Printers working through fine mesh counts (230, 280, 305) for halftone and detail work
• Production runs with long dwell times between colors (multi-station automatic presses)
• Discharge printing workflows where extended open time helps maintain consistent activation
• Any printer transitioning from plastisol to water-based who is not yet accustomed to managing open time

Usage Rates by Application

Compatible Matsui Ink Systems

Retarder MG vs. Spraying Water on the Screen:

Many printers, especially those new to water-based printing, use a spray bottle of water to keep screens moist during production. While this helps temporarily, it introduces several problems that Retarder MG avoids:

How to Use Matsui PrintGen Retarder MG:

Step 1 – Weigh Your Ink: Using a digital gram scale, weigh the amount of ink you need for your production run.

Step 2 – Add Retarder MG: Add 1-5% Retarder MG by weight to the ink. Start at 1-2% for normal conditions and increase to 3-5% for dry environments or fine mesh printing.

Step 3 – Mix Thoroughly: Stir until fully incorporated. Use clean mixing utensils to avoid contamination.

Step 4 – Print and Monitor: Print as normal. You should notice significantly improved open time. If ink still dries too quickly, increase the percentage slightly. If ink is taking too long to cure in the dryer, reduce the percentage on the next batch.

Important Note on Cure Time: Because Retarder MG slows evaporation, it will also extend the time required for the ink to fully cure in your conveyor dryer. At 1-3%, the impact is minimal. At 5% or above, you may need to slow your belt speed or increase dryer temperature slightly to achieve full cure. Always perform a wash test before committing to a production run.

Pro Tips for Best Results:

• Combine with humidity control. Retarder MG works best when shop humidity is at 35% or above. If your shop is consistently below 35%, consider adding a humidifier to your print area. The combination of Retarder MG plus controlled humidity gives the best open time results.
• Use less on automatic presses, more on manual. Automatic presses cycle faster, so ink stays wetter naturally. Manual presses have longer pauses between prints – use a higher percentage to compensate.
• Essential for high mesh halftone work. When printing through 230+ mesh, Retarder MG is not optional – it is critical. The tiny mesh openings dry out extremely fast, and even a few seconds of drying can destroy fine halftone detail.
• Pair with Softener MG for dual benefit. While Retarder MG extends open time, Softener MG lubricates the mesh. Used together (Retarder 1-3% + Softener 1-3%), they provide both anti-drying and improved ink flow for the smoothest possible printing experience.
• Or just use Quick Additive. If you are already using Retarder MG, Softener MG, and Fixer WF-N in most of your mixes, consider switching to Matsui Quick Additive, which contains all three (plus Thickener B) in a single pre-blended product at 7-9%.
• Flood your screens between prints. Even with Retarder MG, always flood the screen after each print stroke. The flood coat creates a fresh layer of wet ink over the image area, providing an additional barrier against drying.
• Keep extra ink on the screen. A thicker reservoir of ink on the screen dries more slowly than a thin film. Do not scrape the screen down to bare minimum between strokes.
• Watch your cure. At higher Retarder MG rates (above 3%), always test cure quality with a wash test. The extra moisture retention that keeps ink open on screen will also require more dryer time to fully evaporate and cure.