When you place a screen printing order, the ink type determines how your design feels on the shirt, how long it lasts, which garment colors work, and whether the print achieves the aesthetic you want. Most buyers never think about ink, they think about design, color, and quantity. But the ink choice made by your print shop affects the final result more than almost anything else.
Three ink types dominate garment screen printing: plastisol, water-based, and discharge. Each works differently at the chemistry level. Each suits different garments, budgets, and aesthetics. This article explains all three accurately, including limitations that most ink comparison pages skip.
Plastisol Ink: The Production Standard for T-Shirts, Hoodies, and Bulk Washington Orders
Plastisol is the most widely used screen printing ink in the garment industry. Approximately 80–90% of screen-printed T-shirts you own are printed with plastisol. It is the default choice in most professional print shops for practical and technical reasons. It is composed of PVC resin and plasticizer, wraps around fabric fibers, and forms a mechanical bond with the fabric at cure temperature. It does not air-dry at room temperature; it remains workable in the screen throughout a production run, which is why it is the preferred ink for high-volume bulk orders. Once cured at 320°F, it bonds permanently.
Plastisol produces high opacity on dark garments, which is why it is the standard for printing white or light-colored logos on navy, black, and charcoal shirts. On dark substrates, a white plastisol underbase is printed first and flash-cured before color layers are applied. The underbase prevents the dark fabric color from bleeding through top ink layers and keeps printed colors true to the original artwork file.
Beyond standard plastisol, NW Custom Apparel produces metallic, puff, high-density, glow-in-the-dark, and fluorescent effects for orders where texture, dimension, or light reactivity adds value to the design. Each effect requires specific mesh counts, cure parameters, and design limitations that standard plastisol does not.
| Specification | Plastisol Ink — Verified Values |
| Full cure temperature | 320°F (160°C) — ink must reach this temperature through the full deposit thickness, not just at the surface |
| Gel point (flash cure) | 240-250°F — partial gel between color layers; not a full cure |
| Best fabrics | 100% cotton, 50/50 cotton-polyester blends — avoid high-polyester content without low-bleed formulation |
| Opacity on dark shirts | High — white underbase required on dark garments before color layers |
| Hand feel | Slightly raised above fabric surface; more tactile than water-based or discharge |
| Dye migration risk | Yes on polyester above 300°F — requires low-bleed formulation on synthetic substrates |
| Wash durability | 25-50+ commercial wash cycles with full cure and correct fabric match |
| Compliance | Phthalate-free, nonhazardous, VOC-free formulation — current industry standard |
Pacific Northwest note: Washington’s climate having cool temperatures and high humidity, affects plastisol curing. Cool ambient temperatures slow heat transfer to the ink deposit in the conveyor dryer. Our production process accounts for seasonal temperature variation in dryer belt speed settings to maintain consistent full cure across all runs.
What Plastisol Does to the Garment
Plastisol ink sits on top of the fabric. It does not penetrate the fibers. The result is a layer of cured ink on the fabric surface – visible, tactile, and opaque.
The tactile quality of a plastisol print depends on the design: a thin single-color logo on a light shirt feels relatively flat, while a multi-color full-chest print on a dark shirt has noticeable texture and weight. This surface layer is also why plastisol can block the underlying garment color — it is opaque in a way water-based ink is not.
Where Plastisol Wins
Color vibrancy on dark garments. Plastisol’s opacity makes it the correct choice when you need bright, saturated color on navy, black, or any dark shirt. With a white underbase printed first and flash-cured, the subsequent colors print on a clean opaque surface. The result is vivid color that is not influenced by the garment color underneath.
Fabric versatility. Plastisol prints on cotton, polyester, cotton-poly blends, nylon, and most performance fabrics. Water-based ink and discharge ink do not work reliably on synthetic fibers. If your order includes polyester moisture-wicking shirts, synthetic safety vests, or tri-blend garments, plastisol is the correct ink.
Durability under standard laundering. A properly cured plastisol print survives 50+ home wash cycles without fading or cracking. The key word is properly cured — under-cured plastisol cracks prematurely. A professional print shop curing at the right temperature with a calibrated conveyor dryer produces prints that outlast the garment.
Production speed at volume. Because plastisol does not dry in the screen and prints wet-on-wet, high-volume runs of 100+ pieces move faster through production with plastisol than with water-based ink. This is one reason it remains the cost-effective choice for bulk orders.
Specialty additive effects. Plastisol is the only ink system that enables dimensional and optical effects. Specialty additive effects built on plastisol base — including puff, high density, metallic shimmer, phosphorescent glow, and photochromic UV change — are achieved by mixing functional additives into the plastisol base before printing. These effects require modified production parameters but produce results no water-based or discharge system can replicate.
Plastisol’s Limitations
Hand feel. Plastisol sits on the fabric surface. Designs feel heavier and more textured than water-based prints. On thin, lightweight cotton T-shirts, a large multi-color print can feel thick. Soft-hand plastisol additives exist and improve this, but they do not eliminate the surface layer.
Environmental footprint. Traditional plastisol contained phthalates — plasticizers now regulated under the Consumer Product Safety Improvement Act (CPSIA) of 2008. Under CPSIA, three phthalate types (DEHP, DBP, and BBP) are banned outright from children’s products, with three more on interim restriction. Modern plastisol formulations from major manufacturers are phthalate-free and the Consumer Product Safety Commission confirms this is now the industry standard. The remaining environmental concern with plastisol is PVC waste and the solvent cleanup process, not cured ink on the garment itself.
Children’s apparel. Phthalate-free plastisol is CPSIA-compliant for most garment applications. However, always confirm your supplier uses certified phthalate-free ink and obtain documentation when printing for children’s products.
Water-Based Ink – Softer Prints, More Production Complexity
Water-based ink penetrates fabric fibers rather than sitting on top of them. The result is a print that feels like part of the shirt rather than a layer applied to it. Water-based ink cures at 300-320°F for 2-3 minutes in a ventilated conveyor dryer — significantly longer than plastisol, because the water in the ink must fully evaporate before the binder and pigment can cure. This extended cure time requires a ventilated dryer chamber to allow steam to escape during the process.
Water-based inks work best on light-colored garments. Opacity on dark substrates is lower than plastisol — a water-based print on a dark shirt requires more ink passes and produces a softer, more translucent result. For fashion T-shirts, premium retail-quality blanks, and orders where hand feel matters more than maximum opacity, water-based ink is the correct choice.
- Best for: Fashion T-shirts, retail blanks, premium event merchandise where softness is the priority
- Mesh count required: 200-305 mesh (higher than plastisol) to prevent ink bleeding beyond design edges
- Color on dark shirts: Limited opacity; not recommended for high-contrast designs on dark substrates without specialty formulation
Water-based inks use water as the primary solvent. Pigments or dyes are suspended in the water with binders and additives that help them bond to fabric fibers. When the printed garment passes through the dryer, the water evaporates and the pigment particles become embedded in the fabric structure.
The result is fundamentally different from plastisol. The ink is not a layer on the surface but inside the fibers.
What Water-Based Ink Does to the Garment
A water-based print on 100% cotton produces the softest, most breathable result of any screen printing method except discharge. The ink permeates the fabric and after the first wash, the print feels identical to the surrounding unprinted fabric. There is no raised edge, no surface texture, no indication that an ink layer exists at all.
This quality is why fashion brands, premium retail apparel, and concert T-shirts often specify water-based printing. The “soft-hand” feel — the absence of any detectable ink texture — is a characteristic only water-based ink produces in standard screen printing.
Where Water-Based Ink Wins
Soft hand feel and breathability. The print does not add weight or block airflow. On lightweight cotton T-shirts worn in warm weather, a water-based print is dramatically more comfortable to wear than plastisol.
Vintage and integrated aesthetic. On dark or colored garments, water-based ink prints at a lower opacity than plastisol. The garment color influences the final print color. A dark red shirt with a white water-based print produces a softer, slightly pinkish tone rather than a sharp, opaque white. This translucency is a feature for brands targeting a worn-in or organic aesthetic.
Environmental profile. Water-based inks contain no PVC and no phthalates. Cleanup requires water rather than solvent-based screen wash. According to the Printing United Alliance, water-based inks generally produce lower VOC emissions during printing than traditional plastisol cleanup processes.
Cotton garment longevity. Because the ink bonds to fabric fibers rather than sitting on top of them, a properly cured water-based print ages with the garment rather than cracking away from it.
Water-Based Ink’s Limitations
Fabric restrictions. Water-based inks require fabric fibers to absorb the pigment. Cotton and high-cotton blends (80%+ cotton) produce good results. On 50/50 poly-cotton blends, results are noticeably softer and less durable. On 100% polyester or synthetic performance fabrics, water-based ink does not bond properly. If your order includes polyester moisture-wicking shirts, you need plastisol.
Dark garment challenges. Achieving bright, opaque color on dark garments requires an underbase layer in water-based printing — which is more difficult to execute than plastisol underbasing because water-based ink is inherently more transparent. Many shops struggle to produce a bright white underbase with water-based ink. The result is often a softer, less saturated color on dark shirts compared to plastisol.
Production demands. Water-based ink dries in the screen when exposed to air. Print runs require more frequent attention, screen maintenance, and moisture management. The emulsion used to create the screen stencil must be water-resistant — standard emulsion breaks down within minutes of contact with water-based ink, according to ScreenPrinting.com. These requirements make water-based printing more technically demanding and slower at volume than plastisol.
Higher production cost. These production complexities like specialized emulsion, careful timing, more labor, typically make water-based printing more expensive per piece than comparable plastisol work. Shops that specialize in water-based printing can bring this cost down, but it remains a premium ink option.
Discharge Ink – Zero Hand Feel on 100% Cotton Only
Discharge ink is a category of water-based ink with a fundamental difference: instead of adding color to the fabric surface, it removes the garment’s existing dye and replaces it with the ink’s pigment. The result is a print that is literally part of the fabric – not on top of it, not penetrating it, but chemically replacing the fiber’s color.
Discharge ink works through a chemical reaction rather than mechanical bonding. A discharge agent in the ink extracts the dye from 100% cotton fabric fibers and replaces it with the ink pigment. The result is a print that sits completely flush with the fabric surface – no raised feel, no texture, indistinguishable from the base fabric by touch.
Critical restriction: Discharge ink works exclusively on 100% cotton fabric with reactive dyes. It does not work on polyester, polyester blends, or cotton garments with pigment dyes. Ordering discharge printing on a 50/50 blend produces a faded, inconsistent result that cannot be corrected after printing. We confirm fabric composition before accepting discharge ink orders.
- Result: Print is flush with fabric surface – zero hand feel, no raised ink layer, vintage washed appearance
- Fabric requirement: 100% cotton with reactive dyes only – no exceptions
- Best for: Premium streetwear, vintage aesthetic designs, soft-hand fashion T-shirts on quality cotton blanks
How Discharge Ink Works
Discharge ink is mixed with a chemical activator before printing. The most common activator is zinc formaldehyde sulfoxylate (ZFS), a reducing agent that breaks the molecular bonds of reactive dyes in cotton when heated. The ink looks pale and unimpressive immediately after printing.
When the garment enters the conveyor dryer and the ink reaches approximately 230°F, the ZFS activator begins reacting with the garment’s reactive dye. By 260°F, dye removal is mostly complete. The garment’s original color is stripped from the fibers in the printed areas, and the pigment in the discharge ink bonds to those now-bleached fibers. The final print color appears only after full curing, which requires reaching the ink’s full cure temperature and holding it long enough for the chemical reaction to complete and all moisture to evaporate.
This process requires a forced-air conveyor dryer specifically. Infrared-only dryers provide radiant heat but cannot vent the steam and formaldehyde gas the reaction produces. Without active airflow, the curing is incomplete — producing ghosting, odor, and prints that fade in the first wash.
If clear discharge base with no pigment is used, the printed area strips back to the natural cotton color — an off-white or cream that creates a bleached, vintage effect. Add pigment to the discharge base, and the printed area takes on that pigment color instead.
Where Discharge Ink Wins
Softest possible hand feel. There is no ink layer at all on the fabric surface. The print area feels identical to the surrounding unprinted fabric. After the first wash, residual surface ink washes away and the print integrates completely. This is not achievable with plastisol or standard water-based printing.
Premium prints on dark cotton. When executed correctly on the right garments, discharge produces prints on dark shirts that feel like they came from the factory that way. For fashion brands, concert merchandise, and premium retail T-shirts, this is the preferred result.
Eliminates the heavy underbase. In standard plastisol printing on dark garments, a white underbase adds a thick ink layer that increases the print’s weight and hand feel. Discharge removes the dark dye before printing color — no underbase needed in most applications. The result is a thinner, more integrated print even in multi-color designs.
Hybrid technique: discharge-as-underbase. Experienced screen printers use discharge ink as the underbase layer, then print plastisol colors on top. The discharge removes the dark garment dye first, creating a soft, bleached surface. The plastisol colors then print on that base with full vibrancy — achieving bright color with a significantly softer underbase than pure plastisol.
Discharge Ink’s Limitations
100% cotton with reactive dyes only. Discharge chemistry requires reactive or direct dyes in the fabric for the reaction to work. Polyester, nylon, and synthetic fabrics use dye processes that the ZFS activator cannot strip. High-cotton blends work partially — the cotton fibers discharge while synthetic fibers retain their original color, producing an uneven or textured result that can be intentional or disastrous depending on the design.
Re-dyed garments resist discharge unpredictably. Manufacturers sometimes re-dye overstock in popular colors — most often black. These garments contain multiple dye layers and resist discharge or produce blotchy, inconsistent results. Re-dyed shirts are usually identifiable by their particularly soft washed feel, nearly-universal black color, and stained woven neck labels (from dye applied after assembly). Always request discharge-rated garments from your supplier and confirm with a swab test on a production sample before committing to the full run.
Pot life limitation. Once the ZFS activator is mixed into the discharge base, the ink has a working life of approximately 4–8 hours. Print shops cannot store activated discharge ink overnight. Activated ink must be remixed every 30–45 minutes during a run to prevent inconsistency. Shops mixing only what they need for each run manage this well, but it adds production complexity.
Formaldehyde requires ventilation. The ZFS discharge reaction releases trace formaldehyde gas during curing. Professional shops run discharge printing with properly vented dryers and adequate airflow. Finished garments have measurable formaldehyde levels immediately post-cure that dissipate over several days when the garments are unpackaged. For this reason, discharge ink is not CPSIA-certified for children’s apparel. If you are printing garments for children or need certified-safe inks, use phthalate-free plastisol or water-based ink.
Thiourea dioxide alternative. Some shops use thiourea dioxide as the discharge activator instead of ZFS. This system produces lower formaldehyde emissions and is considered the newer, lower-risk option. It is less widely used than ZFS and produces slightly different results depending on the garment. If formaldehyde is a concern for your order, ask whether your printer offers a thiourea dioxide discharge option.
Which Ink Is Right for Your Order
As a buyer placing a custom apparel order — not running a press yourself — the ink type question simplifies significantly. You care about three things: how the print feels, how long it lasts, and whether it achieves the look you want.
| Your Priority | Best Ink |
|---|---|
| Brightest, most vivid color on dark shirts | Plastisol with white underbase |
| Prints on polyester, performance fabric, or blends | Plastisol |
| Softest possible feel on light-colored cotton | Water-based |
| Vintage or faded aesthetic on any cotton | Water-based |
| Absolute softest feel on dark cotton — no surface texture | Discharge (100% reactive-dyed cotton required) |
| Children’s apparel | Phthalate-free plastisol or water-based |
| Bulk order (100+ pieces) at lowest cost per piece | Plastisol |
| Premium fashion or retail T-shirt | Water-based or discharge |
| Hi-Vis safety shirts for ANSI compliance | Plastisol only |
For most Washington state businesses ordering branded work shirts, event T-shirts, or promotional apparel, plastisol is the correct choice. It handles any fabric, produces reliable color, and delivers durable results at bulk volume pricing.
For brands ordering premium retail T-shirts where hand feel is the primary requirement, water-based or discharge ink produces a result plastisol cannot.
How This Affects Your Order at NW Custom Apparel
NW Custom Apparel uses plastisol ink as the standard for screen printing production. Water-based ink is available by request for 100% cotton orders where hand feel is the priority. Discharge printing availability depends on current production scheduling — contact us to discuss.
For bulk orders where screen printing is the right method, see our screen printing services for bulk Washington state orders. For event and team T-shirts at quantity, see bulk screen printed T-shirts for teams and events. And For construction and trades crews requiring ANSI-certified Hi-Vis workwear, see Hi-Vis screen printing for ANSI-compliant workwear.
If your design has unlimited colors, photographic detail, or you need fewer than 24 pieces, DTG printing for designs that need a softer feel without screen printing setup costs is likely the better method.
Not sure whether screen printing, DTG, or DTF fits your specific order? See our comparison of screen printing, DTG, and DTF for your specific garment and order size, or read our full breakdown of embroidery versus screen printing for work uniforms.
Frequently Asked Questions
Both are durable when cured correctly, but in different ways. Plastisol on cotton survives 50+ home wash cycles with minimal change when properly cured at 300–330°F. Water-based prints, because the ink bonds to the fiber rather than the surface, also last the life of the garment when cured with a forced-air dryer at adequate temperature. The difference shows under commercial laundering (high heat, industrial detergent, industrial drying): plastisol degrades faster than embroidery in that environment, and water-based on cotton holds comparably. Discharge prints, because the dye is chemically replaced rather than added, are arguably the most wash-durable of the three, there is nothing on the fabric surface to crack or peel.
Hand feel describes the tactile quality of a printed design on the garment. A heavy hand feel means you can clearly feel the ink layer sitting on the fabric surface that is common with thick plastisol prints. A soft hand feel means the print is nearly undetectable by touch which is common with water-based and discharge prints where the ink enters or chemically integrates with the fabric fibers.
Yes, if your order is 100% cotton garments and you are willing to accept a slightly higher per-piece cost to reflect the additional production complexity. Water-based printing produces results on cotton that plastisol cannot match for softness. On polyester or poly-blend garments, water-based ink does not bond reliably, so plastisol remains the correct choice regardless of preference.
Discharge ink works by chemically breaking the molecular bonds of reactive dyes in the fabric. Cotton dyed with reactive dyes contains those breakable bonds. Polyester and other synthetic fabrics use different dye processes, the ZFS or thiourea dioxide activator in discharge ink cannot react with those dyes. Printing discharge on synthetic fabric produces no dye removal, resulting in a pale, poorly-bonded print that washes out quickly.
Modern phthalate-free plastisol ink, which is now the industry standard since CPSIA 2008 regulations, is safe for standard adult apparel applications. The CPSIA specifically regulated phthalate content in children’s products for sleeping and feeding purposes. Modern major ink manufacturers produce phthalate-free formulations that comply with these requirements. For children’s apparel, always confirm your printer uses CPSIA-compliant phthalate-free plastisol or switches to water-based ink entirely.
Both use a bleaching mechanism on cotton fabric. Discharge ink uses a chemical activator (ZFS or thiourea dioxide) that selectively removes reactive dye from the fabric in a controlled manner, often replacing it with a specific pigment color. Bleach printing uses household bleach applied to the garment surface, which removes dye less selectively and cannot be controlled with the same precision as discharge chemistry. Discharge printing is a professional production method. Bleach printing is a DIY technique with unpredictable results and less predictable longevity.
The Bottom Line
Three inks. Three different approaches to putting color on fabric.
Plastisol sits on the surface, cures reliably, works on any fabric, and produces the most opaque, vibrant results. It is the standard for a reason. Water-based penetrates the fibers, produces a softer and more breathable print, and works best on cotton. Discharge chemically removes and replaces the garment’s dye, producing a print that is structurally part of the fabric with no surface layer at all, but it only works on 100% reactive-dyed cotton and requires precise production conditions.
For most custom apparel orders, plastisol is the right starting point. For fashion or premium retail T-shirts on 100% cotton, water-based or discharge is worth the conversation. Ask your printer which ink they are using and why. A knowledgeable shop will explain the choice rather than defaulting to whatever is most convenient to run.
NW Custom Apparel has produced screen printing in Washington state since 1977. Contact our team to discuss which ink type fits your specific garment, design, and use case.
Get a Screen Printing Quote | Call 253-922-5793
About the Author
Erik Mickelson is the Operations Manager at Northwest Custom Apparel in Milton, Washington. He has worked in custom apparel production for 29 years and founded the Apparel Graphic Academy, a product evaluation framework for blank garments and decoration methods. He holds a degree from Washington State University.
