Sublimation turns ink into gas under heat and bonds it into the surface of the material. The design becomes part of the item rather than sitting on top of it, which is why a sublimated shirt has no texture where the print is and does not crack after washing.
That process puts specific demands on the file you start with. A PNG that looks perfect on screen can still produce a disappointing transfer, and almost always for one of the same five reasons.
The file specs that matter
Transparent background. Non-negotiable. Sublimation ink does not print white — white areas simply come out as the colour of the blank. A design saved on a white square will not show a white box, but every edge and gap will pick up the blank colour in a way you did not intend. Open the file and confirm you see a checkerboard, not white.
300 DPI. The print standard. Files at 72 DPI are built for screens and will look soft once heat-pressed.
Generous pixel dimensions. For an adult shirt front you want roughly 3600 pixels across, which gives a 12-inch print at 300 DPI. Anything smaller restricts you to pockets, mugs and children sizes.
Clean edges. Zoom to 200 percent and look at the outline. Ragged or semi-transparent fringing that is invisible on screen becomes a grey halo on a pale blank.
Which blanks actually work
This is where most beginners lose money. Sublimation needs two things from the material: polyester content and a light colour.
- 100% polyester gives the brightest, most durable result.
- 65% polyester blends work but come out softer and slightly faded — some sellers market this deliberately as a vintage look.
- Cotton does not work. The ink has nothing to bond with and washes out.
- Hard blanks — mugs, tumblers, coasters, slate — need a special polymer coating. An ordinary mug will not take sublimation.
- Dark or black fabric does not work. Sublimation ink is translucent, so the garment colour shows through and a dark blank swallows the design.
Sublimation or DTF
If you want cotton, or dark garments, sublimation is the wrong process. Direct-to-film prints the design onto a film with a white ink layer behind it, then transfers it with heat.
Sublimation: softest feel, most durable, but light polyester only.
DTF: works on cotton, blends and dark colours, but you can feel the print slightly and it wears a little faster.
The same PNG file works for both. Only the process and the blank change, which is worth knowing before buying a bundle — you are not locked into one method.
Where to find your settings
Time, temperature and pressure vary by blank, by press and by paper, so there is no universal table worth trusting. What does work is a method.
Start from the blank supplier figures. They tested that specific product and their numbers are a better starting point than a generic chart.
Change one variable at a time. If a result is too faint, adjust time before temperature. Changing both leaves you unable to tell which mattered.
Write everything down. Blank, press, temperature, seconds, pressure, result. A page in a notebook beside the press saves you repeating the same failed test in three months.
Test on the cheapest version of the blank. Work out the settings on a plain tote, not on the shirt somebody has paid for.
Presses also run hotter or cooler than their display. If your results consistently differ from the supplier figures, the press is usually why, and an infrared thermometer settles it in a minute.
Organising the files when you open a bundle
A forty-design bundle arrives as a folder of numbered files, which is useless in six months when you are looking for one specific ghost.
Spend ten minutes at the start. Create subfolders by type — characters, lettering, small motifs, composed layouts — and rename anything you use more than once with a description rather than a number. Keep the original download untouched in its own folder and work only on copies, so a flattened or resaved file never overwrites the source you paid for.
Keep a note of where each bundle came from and what its licence permits. If you sell, you may need to show that record later, and reconstructing it from an old email thread is considerably harder than writing one line now.
The designs
Both sets below are supplied as individual PNG files with transparent backgrounds.
View on Etsy: 42 Halloween PNG Bundle · 12 Fall Pumpkin PNG Bundle. Check each listing for exact file dimensions and licence terms before selling anything made with them.
Five mistakes that waste transfers
- Forgetting to mirror. Sublimation prints in reverse. Any lettering that is not mirrored before printing comes out backwards, and you find out after pressing.
- Enlarging a small file. Scaling a 1200-pixel design up to shirt size produces visible softness. Scale down, never up.
- Judging colour on screen. Sublimation colours shift, often noticeably. Oranges, terracottas and dusty pinks are the least predictable, which makes autumn palettes the ones most worth testing first.
- Skipping the lint roll. A single hair or fibre on the blank leaves a permanent white line through the design.
- Guessing time and temperature. Every blank differs. Follow the supplier figures and write down what worked.
A sensible first project
Start with a white polyester tote bag and one simple design without small text. It is cheap, flat, forgiving, and it teaches you the whole sequence — size, mirror, print, press, peel — without the cost of a ruined shirt.
Once that works, move to a light shirt, then to mugs, which need a wrap press and are the fussiest of the common blanks.
Frequently asked questions
Can I sublimate onto cotton?
No. Sublimation needs polyester or a polymer coating. Use DTF or heat transfer for cotton.
Do I have to mirror the image?
Yes, for sublimation. Printing unmirrored is the single most common beginner error.
What resolution do I need?
300 DPI, with enough pixels for the finished size — about 3600 across for an adult shirt front.
Why does my design have a faint outline?
Semi-transparent edge pixels in the file, or a background that is not fully transparent. Check the edges at high zoom.
Where do I get the right time and temperature?
From the blank supplier, then adjust one variable at a time and record what worked.
Can I sell what I make?
Only if the listing grants commercial use. Read the licence on that specific listing.
More design resources
These guides sit alongside our Halloween printables collection.
- Halloween PNG Bundle — what is inside and what to make
- Fall Pumpkin PNG Bundle — three design styles
- Halloween Crafts for Kids
- Halloween Coloring Pages for Kids