Discharge ink and regular screen printing ink can both produce durable, professional garments, but they create the image in very different ways. Regular plastisol places a cured layer of color on the fabric. Discharge ink chemically removes or changes the garment dye and replaces it with a new color, producing a print with very little surface feel.

Discharge is often the better choice for soft prints on compatible dark cotton. Regular plastisol is more predictable, easier to manage, and suitable for a much broader range of fabrics.

What Is Regular Screen Printing Ink?

In this comparison, regular ink refers primarily to plastisol. Plastisol remains wet in the screen until it is exposed to sufficient heat, making it dependable for manual printers, automatic production, and jobs with interruptions.

Regular plastisol is available in formulas designed for:

Our 480 Series is an easy-printing general-purpose plastisol for light cotton and poly/cotton garments or for printing over a white underbase. It is also well suited to wet-on-wet production.

What Is Discharge Ink?

Discharge ink is generally a water-based system containing an activator. During curing, the activated ink reacts with compatible garment dye and removes or neutralizes the original color in the printed area.

A clear discharge base can reveal the natural color of the underlying cotton. Pigments can also be added to produce colored discharge prints.

Because the garment dye is removed rather than covered with a thick opaque layer, the finished print can become part of the fabric and have almost no noticeable surface deposit.

Discharge Produces The Softest Feel

The primary advantage of discharge ink is its extremely soft hand. It is particularly useful for large solid graphics on dark shirts that would otherwise require a heavy white underbase.

Discharge works well for:

Regular plastisol sits more noticeably on the fabric, especially when a white underbase and several top colors are used. Its feel can still be reduced through higher mesh counts, thinner stencils, controlled pressure, and soft-hand ink formulas.

Regular Ink Is More Predictable

Plastisol covers the garment color instead of depending on a chemical reaction with the garment dye. This generally makes the final color more consistent from one shirt to another.

Discharge results depend heavily on how the garment was dyed. Two black shirts that appear identical may discharge to different shades because they were manufactured with different dye combinations.

A discharged black garment may reveal:

This variation is not necessarily caused by the ink. It is often a characteristic of the garment dye.

Best Fabrics For Discharge Ink

Discharge performs most predictably on 100% cotton garments dyed with dischargeable reactive dyes. Cotton-rich blends may also work, but the synthetic fibers will not discharge in the same manner as cotton.

A cotton/polyester blend may produce a heathered or muted result because the cotton portion changes while the polyester fibers retain their original color.

Discharge is generally a poor choice for:

When garment content or dye chemistry is uncertain, regular plastisol is usually the safer production choice.

Best Ink For Polyester

Discharge does not solve polyester dye migration. Polyester requires an ink formulated to block or resist dyes while curing with as little damaging heat as practical.

Our ELT Series is designed for low-temperature curing, bleed resistance, stretch, and broad fabric compatibility. It can cure at temperatures as low as 250°F, helping reduce shrinking, scorching, ghosting, and other heat-related problems.

Use discharge primarily for compatible cotton. Use a low-cure, bleed-resistant plastisol for polyester and performance apparel.

Discharge Ink Must Be Activated

Many discharge systems require a measured amount of activator to begin the dye-removing reaction. Once activated, the ink has a limited working life.

The exact activator percentage and pot life depend on the product. Never estimate the amount or assume that all discharge systems use the same formula.

For consistent production:

  1. Mix the unactivated ink thoroughly.
  2. Weigh only the amount needed for the job.
  3. Add the specified activator by weight.
  4. Record the activation time.
  5. Use the mixture within its stated pot life.
  6. Never return activated ink to the original container.

Expired discharge ink may still look printable while no longer removing the garment dye or curing properly.

Regular Plastisol Is Easier To Store And Reuse

Unmodified plastisol does not have an activated pot life. It can be removed from a clean screen and returned to its labeled container for future use.

Properly stored One Stroke Inks plastisol should remain usable indefinitely when it is kept at room temperature, protected from direct heat, and free from contamination.

This makes regular ink more convenient for:

Screen And Emulsion Requirements

Discharge is water-based and requires a stencil capable of resisting water-based ink. An emulsion selected only for plastisol may soften or break down during a long discharge run.

Saatichem Graphic HU 42 is a dual-cure emulsion suitable for plastisol, solvent, and water-based ink. It provides fine detail and can be made more water resistant through proper post-exposure.

Discharge ink can also begin drying in the mesh. Keep the image flooded during pauses and clean the screen promptly after printing.

Plastisol does not normally dry in the screen, making it more forgiving during delays, registration changes, and manual production.

Underbase Differences

Regular ink usually requires a white underbase to produce bright colors on dark garments. The underbase adds opacity but also increases print thickness, flashing, and curing requirements.

Discharge can eliminate the need for a conventional white underbase when the garment discharges cleanly. Colored discharge ink can then produce a soft design directly on the dark fabric.

However, discharge should not be chosen solely to avoid printing an underbase. An unreliable garment may produce a worse result than a properly printed plastisol base.

Curing Discharge Ink

Discharge curing must accomplish two things: complete the dye-removing reaction and cure the ink binder. A visible color change alone does not prove that the print is durable.

Insufficient heat or dwell time may produce:

Follow the cure instructions for the exact discharge system. Test the actual garment, allow it to cool, and perform a complete wash-and-dry test.

Regular plastisol also requires complete curing through the entire ink deposit. Neither ink should be approved by appearance alone.

Ventilation And Handling

Activated discharge ink may create a noticeable odor during printing and curing. Use effective ventilation and follow the label and Safety Data Sheet for the base, pigment, and activator.

Keep children, food, and drinks away from the work area. Wear the protective equipment recommended for the specific system and avoid breathing vapors released near the dryer.

Do not assume that water-based means harmless or that a low-odor discharge product needs no ventilation.

Production Speed And Cost

Discharge may reduce the number of heavy underbase layers and flashes required for a dark cotton job. It may also support soft wet-on-wet printing when the complete system and artwork are designed for it.

However, its total cost also includes:

Regular plastisol may use more ink and flashing, but it is generally more repeatable and can be reused after the job.

Compare the complete production cost rather than assuming discharge is cheaper because it uses a thinner deposit.

When To Choose Discharge Ink

Choose discharge when:

When To Choose Regular Ink

Choose regular plastisol when:

Test Every Discharge Garment

Never approve discharge ink based only on fiber content or garment color.

  1. Print the actual garment.
  2. Use the planned activator, mesh, and deposit.
  3. Cure it according to the ink instructions.
  4. Allow it to cool completely.
  5. Inspect the discharged color and consistency.
  6. Wash and dry the sample.
  7. Retain the approved garment for production comparison.

Testing several garments from the order is especially valuable when the shipment may contain different dye lots.

Final Thoughts

Discharge ink is the better choice when a compatible dark cotton garment needs an exceptionally soft, breathable print. It can remove the need for a heavy white underbase and create a premium retail-style result.

Regular plastisol is more versatile and predictable. Use the 480 Series for general cotton and poly/cotton production, and choose the low-cure ELT Series for polyester, blends, and heat-sensitive garments.

For a soft hybrid approach on compatible black cotton, the Watercolor Series can be combined with a discharge base.

The final decision should be based on the garment, required feel, color predictability, available equipment, and production risk. Discharge can produce an outstanding result, but only after the actual garment has passed a complete print, cure, and wash test.