White Ink Underbase
The opaque white layer printed underneath the CMYK color, the reason a DTF transfer looks like the file on a black shirt instead of a ghost of it.
Short version, straight from the floor.
The white ink underbase is a heavy deposit of pigment-loaded white ink laid down on the film before the color layer prints. Without it, CMYK ink is translucent. Yellow on a black shirt looks like dark olive.
Trusting a supplier that will not publish their underbase density. If a DTF vendor cannot tell you their target grams per square meter or their cure temperature, they are running whatever the printer defaults are. That is why their transfers peel and yours will too. Ask the number.
Assuming the underbase is what makes a shirt soft. Hand is a function of underbase density plus adhesive powder grain plus how thick the color layer is. Blaming a stiff transfer on the underbase alone is why shops keep asking for less white and then wonder why the transfer looks washed out. Adjust the whole stack, not one layer.
Trying to add underbase after the color is already on the film. The underbase is printed first, then color on top. Reversing the order puts CMYK against the fabric and white on the outside, which is the wrong finish and destroys wash durability. Reprint the file, do not try to save the sheet.
Ignoring underbase on hoodie sleeves. Sleeves get abraded more than the chest. If a shop reduces underbase to soften hand on a hoodie, the sleeves crack first. Full underbase on any placement that will see friction.
A production-floor definition, not a spec-sheet lift.
The white ink underbase is a heavy deposit of pigment-loaded white ink laid down on the film before the color layer prints. Without it, CMYK ink is translucent. Yellow on a black shirt looks like dark olive. Red looks like maroon. With a proper underbase, the color prints against a white background instead of a dark fabric, and the file on your screen finally shows up on the garment.
Density is the whole game. Underbase that is too thin ghosts the color. Underbase that is too thick cracks in the wash and stiffens the hand. Golden DTF runs a variable-density underbase profile that reads the incoming file, calculates how much color is stacked over each pixel, and lays only as much white as the color layer needs. On a solid black-fill area we push heavy. On a subtle gradient we back off. It is the difference between a transfer that lasts 60 washes and one that lasts 12.
The underbase also sits between the CMYK layer and the adhesive powder. That interface matters. If the underbase is not fully cured before powder application, the powder sinks into the wet ink and never grabs the fabric during press. This is the failure mode behind most peeling transfers from budget suppliers. Their cure lamp is undersized, their line speed is too fast, and the underbase is still soft when the powder hits it.
You do not order the underbase separately. It ships with every full-color DTF transfer Golden DTF prints on dark or medium shirts. On light and white shirts we print white-off , the underbase is either skipped entirely or reduced to preserve fabric hand. Ask if you want the underbase spec called out on your order card.
Every field you need before the press cycle starts.
The numbers below come from our own production floor, not a supplier tech sheet. If a field says 305 F, it is because we press at 305 F and it works. If a field says "avoid on tri-blend," it is because we ruined a run and stopped doing it.
Physical
- Ink type
- Water-based pigment, high-loading TiO2 white
- Deposit range
- 10 to 45 grams per square meter, variable per pixel
- Cure temp
- 230 F cure lamp before powder application
- Opacity target
- Minimum 92% opaque over black measured under standard light
Behavior on garment
- Fabric compatibility
- All fabrics; density adjusted for cotton, blend, tri-blend, performance
- Dye migration blocker
- Partial; combine with poly blocker formula on high-poly light-color art
- Wash durability
- 60-plus washes when properly cured; cracks by wash 20 if under-cured
- Hand feel
- Adds slight body to design; heavier on dense underbase areas
- Opacity on black cotton
- Full color, no ghosting, holds gradient
- Opacity on black poly
- Full color for 8 to 12 weeks; add poly blocker for permanent hold
Decoration compatibility ranking
- DTF transfer
- Required on medium/dark garments, optional on light
- Screen print
- Screen printers underbase with a separate flash-cured white; different process
- Sublimation
- Not applicable; sublimation only prints on white or light poly
- UV DTF
- Not required; UV DTF is a hard-goods method, not garment ink
Failure modes
- Under-cured underbase
- Powder sinks, transfer peels at wash 12
- Over-thick underbase
- Cracks along fold lines by wash 30
- No underbase on darks
- Ghost image, colors look 40% desaturated
- Underbase on whites
- Unnecessary hand and stiffness with no visible benefit
What this is designed to run next to.
Every pairing below is one we set on the press ourselves. If a substrate or transfer type is not here, it is either wrong for this material or we have not proven it enough to publish.
Best-with films
Best-with formulas
Where this is the wrong tool, and what to reach for instead.
You are pressing on a pure-white cotton shirt.
The fabric is already the color the underbase would provide. Skipping it saves hand, saves ink cost, and speeds cure. On white cotton we print white-off unless the customer requests underbase for consistency.
You need a super-soft hand for a fashion line.
Underbase adds body. If the whole selling point of your line is a barely-there print, DTF may be the wrong method. Screen print with a discharge underbase gives near-zero hand on cotton. Note that this is a screen-print recommendation, not a DTF one.
Your art is a single spot color on a light shirt.
A one-color print on a light garment does not need underbase to be legible. Adding it slows the press cycle and stiffens the design. Print the color layer directly, save the underbase for when the shirt is trying to swallow the ink.
The failures we watch shops repeat every week.
Trusting a supplier that will not publish their underbase density.
If a DTF vendor cannot tell you their target grams per square meter or their cure temperature, they are running whatever the printer defaults are. That is why their transfers peel and yours will too. Ask the number.
Assuming the underbase is what makes a shirt soft.
Hand is a function of underbase density plus adhesive powder grain plus how thick the color layer is. Blaming a stiff transfer on the underbase alone is why shops keep asking for less white and then wonder why the transfer looks washed out. Adjust the whole stack, not one layer.
Trying to add underbase after the color is already on the film.
The underbase is printed first, then color on top. Reversing the order puts CMYK against the fabric and white on the outside, which is the wrong finish and destroys wash durability. Reprint the file, do not try to save the sheet.
Ignoring underbase on hoodie sleeves.
Sleeves get abraded more than the chest. If a shop reduces underbase to soften hand on a hoodie, the sleeves crack first. Full underbase on any placement that will see friction.
Materials this is often confused with.
Order transfers with the underbase spec on the order card.
Every Golden DTF transfer ships with the underbase density recorded and QC'd. Ask us to write the deposit target on your order card and we will send it with the shipment.