Matsui Catalyst 3000/RV Additive | Viscosity Reducer and Fabric Penetration Enhancer for Water-Based Screen Printing Ink

Matsui Catalyst 3000/RV Additive — The Official Ink Thinner for Every Matsui Water-Based Ink System

Every ink system needs a viscosity reducer. In the Matsui water-based product line, that product is Catalyst 3000/RV Additive.

If you look at the technical data sheet for any Matsui ink — 301 RC bases, Alpha Series, Infinity Series, Stretch Clear, Simple Clear, EasyPrint White, Dye Blocker, Kombat Blocker, Discharge bases, Puff Foaming Base, Glitter Base, Pearl Binder, Crack Base, Suede Base, Flock Binder, Foil Adhesive, Foil Blocker, Phantom Clear, Hydrochromic White, Soft-Tex Overprint — every single one lists “RV Additive” as the designated thinner. It is the universal viscosity control additive for the entire Matsui ecosystem.

But Catalyst 3000/RV Additive is not just a thinner. Unlike simply adding water to thin your ink (which dilutes the resin system and weakens the print), RV Additive reduces viscosity while simultaneously improving three other critical print properties: fabric penetration, cross-linking during cure, and ink-to-fiber adhesion. This is why Matsui calls it “Catalyst 3000” — it catalyzes a better bond between ink and garment, not just a thinner ink.

What RV Additive Actually Does — Viscosity Reduction vs. Adding Water

This is the most important distinction to understand about RV Additive, and it is the question that brings most printers to this product: Why can’t I just add water to thin my ink?

You can add small amounts of water to Matsui inks to rehydrate ink that has started to dry. But using water as a viscosity reducer creates problems:

Bottom line: Water rehydrates. RV Additive reduces viscosity while simultaneously making the ink penetrate better, bond stronger, and cure more effectively. They are not interchangeable.

Matsui Catalyst 3000/RV Additive Key Features:

• Reduces Ink Viscosity: Thins out water-based ink to improve flow through the mesh without diluting the resin system or weakening the ink film. The recommended 1-3% dosage provides measurable, controlled viscosity reduction.
• Enhances Fabric Penetration: Drives the ink deeper into fabric fibers, creating prints that are more integrated with the garment. This results in a softer hand feel, better adhesion, and improved durability because the ink is mechanically locked into the fiber structure rather than sitting on the surface.
• Promotes Cross-Linking During Cure: RV Additive actively improves the chemical cross-linking that occurs during the heat cure process. Cross-linking creates stronger molecular bonds between the ink resin and garment fibers, which directly improves wash fastness and crock resistance.
• Improves Adhesion on Difficult Substrates: Particularly effective on polyester, cotton-poly blends, thick or heavyweight garments, and tightly-woven fabrics where standard ink may struggle to penetrate or adhere properly.
• Universal Matsui Compatibility: Designated as the official thinner/viscosity reducer in the technical data sheets of every Matsui water-based ink product. Works across 301 RC, Alpha, Infinity, Stretch, Simple, EasyPrint, Discharge, all special effect inks, and all Matsui mixing bases.
• Works with Both Water-Based and Discharge Inks: Compatible with standard water-based printing and with activated discharge inks, expanding its usefulness across your entire production workflow.
• No Pot Life Limitation: RV Additive does not expire once mixed into your ink. Your mixed batch remains usable indefinitely, allowing for pre-mixed inventory.
• Does Not Alter Color or Appearance: At the recommended 1-3% dosage, RV Additive does not change ink color, opacity, or surface appearance.
• Compatible with Photopolymer Emulsions: Safe for use with photopolymer-based stencils — does not attack or degrade the emulsion.
• PVC-Free: Environmentally safe formulation consistent with the Matsui PVC-free product line.

Why Screen Printers Use Matsui RV Additive:

RV Additive solves a specific set of production problems that water-based screen printers encounter regularly. Understanding when to reach for it — and when another additive is the better choice — is key to getting the most out of it.

The Real-World Problems RV Additive Solves:

• “My ink is too thick and won’t flow through the mesh cleanly.” This is the #1 reason printers use RV Additive. Inks that are too viscous produce inconsistent deposits, leave mesh marks, require excessive squeegee pressure, and create fatigue on manual presses. Adding 1-2% RV Additive reduces viscosity to improve flow without compromising print quality.
• “I’m printing through high mesh (230+) and the ink is struggling to pass through.” High mesh counts restrict ink flow because the openings are smaller. Thicker inks that print fine through 110 or 156 mesh may struggle at 230 or 305 mesh. RV Additive at 1-2% brings the viscosity down to a range that passes smoothly through fine mesh without losing opacity or sharpness.
• “My prints aren’t penetrating the fabric — they feel like they’re sitting on top.” If the ink is not absorbing into the garment fibers, it sits on the surface, feels stiffer, and is more vulnerable to cracking and washing off. RV Additive promotes deeper fabric penetration, which improves both hand feel and print durability. This is especially useful on heavyweight garments (6+ oz), tightly woven fabrics, and polyester blends.
• “I’m having adhesion issues on polyester or blended fabrics.” Polyester and synthetic-blend garments can be difficult for water-based inks because the synthetic fibers resist absorption. RV Additive’s penetration and cross-linking properties improve the ink-to-fiber bond on these substrates, reducing adhesion failure.
• “My prints are losing vibrancy or cracking after a few washes.” If the ink isn’t properly bonded to the garment fibers, wash fastness suffers. RV Additive promotes cross-linking during the cure, which strengthens the molecular bond between the ink resin and the fabric. This is especially valuable on garments that will see frequent, aggressive washing.
• “I need to thin my ink but don’t want to weaken it with water.” This is the fundamental value proposition. Adding water dilutes the resin, weakens adhesion, and can cause incomplete curing. RV Additive thins the ink while actually improving the properties that water would weaken.

RV Additive vs. Other Matsui Additives — When to Use Which

Printers sometimes confuse RV Additive with Softener MG because both improve ink flow and fabric penetration. They are different products with different mechanisms and different primary purposes:

Key distinction — RV Additive vs. Softener MG for penetration: Both improve fabric penetration, but through different mechanisms. Softener MG reduces surface tension via silicone, which allows the ink to spread and absorb more easily. RV Additive reduces viscosity directly, making the ink physically thinner so it flows into the fiber structure more readily. Both work. They can be used together. But if your primary need is viscosity reduction and adhesion improvement, RV Additive is the correct choice. If your primary need is a softer hand feel with a silicone-smooth finish, Softener MG is the correct choice.

Can you use both? Yes. Many printers use both RV Additive (1-2% for viscosity) and Softener MG (2-3% for hand feel) in the same batch when they need both thinner ink and a softer finish. The two additives complement each other without overlap.

How to Use Matsui Catalyst 3000/RV Additive

Step 1 — Weigh Your Ink: Place your mixed Matsui ink on a scale and record the weight.

Step 2 — Calculate the Dosage: Add 1-3% RV Additive by weight. Start at 1% for a slight viscosity reduction. Go to 2-3% for more significant thinning or when you need maximum penetration improvement on thick or synthetic fabrics.

Step 3 — Mix Thoroughly: Add the calculated amount of RV Additive to your ink and stir slowly but consistently using clean utensils. Continue mixing until the additive is completely integrated with no visible clumps or streaks.

Step 4 — Test Print: Run a test print to evaluate the viscosity and penetration. If the ink is still too thick, add another 0.5-1% in small increments. Do not exceed 3% without testing, as over-thinning can affect print quality.

Step 5 — Print and Cure Normally: No changes to your print process or cure settings. RV Additive does not alter cure temperature requirements. Cure at your standard 320°F (160°C) for the recommended dwell time of your base ink.

Pro Tips for Best Results

• Do not exceed 3% without testing. Over-thinning the ink can cause it to flow too freely, resulting in blurry details, excessive bleeding, or insufficient opacity. Stay within the 1-3% range and test before committing to production.
• Use RV Additive — not water — as your primary thinner. Water rehydrates dried ink but dilutes the resin system. RV Additive reduces viscosity while improving penetration and cross-linking. They serve fundamentally different purposes.
• Combine with Thickener B for fine-tuning. RV Additive (thinner) and Thickener B (thickener) are the designated viscosity control pair across all Matsui inks. If you thin too much with RV Additive, you can add Thickener B (0.25-1%) to bring the viscosity back up.
• Essential for high mesh printing. If you are printing through 230+ mesh and experiencing inconsistent ink transfer, mesh marks, or incomplete fills, 1-2% RV Additive is often the solution. The thinner viscosity allows the ink to pass cleanly through the smaller mesh openings.
• Particularly useful on heavyweight garments. Thick, densely-woven fabrics (10+ oz fleece, heavyweight hoodies, canvas) resist ink penetration. RV Additive at 2-3% helps the ink absorb into the fiber structure rather than sitting on top, which improves both hand feel and wash durability.
• Improves adhesion on polyester and blends. If you are printing on 100% polyester or high-poly blends and experiencing adhesion problems (ink peeling or cracking), RV Additive’s cross-linking properties can help. For polyester, also consider pairing with Dye Blocker or Kombat Blocker as your underbase to prevent dye migration.
• Works with both water-based and discharge inks. RV Additive is not limited to standard water-based printing. It can be mixed into activated discharge inks as well.
• Use with clean mixing vessels and utensils. As with all Matsui products, contamination from other ink sources or non-approved additives can compromise the PVC-free certification. Always use clean, dedicated equipment.
• Pair with other Matsui additives as needed. RV Additive works alongside the full Matsui additive lineup. A typical production recipe might include: Retarder MG (1-3%) for open time + Softener MG (2-3%) for hand feel + Fixer WF-N (1-3%) for wash fastness + RV Additive (1-2%) for viscosity and penetration. All four can be used together in the same batch.