Why Sublimation Paper Matters More Than You Think
Sublimation paper is the link between your printer and your finished product. Get it right and your colours will be vivid, your lines sharp, and your transfers clean. Get it wrong and you will end up with faded prints, ink bleeding, or transfers that simply do not stick. This guide covers how to identify the correct printing side, how to store your paper properly, and the key mistakes to avoid when using it.
Identifying the Coated Side
Every sheet of sublimation paper has a coated side and an uncoated side. The coated side is specifically treated to receive and hold sublimation ink, then release it cleanly during the heat press stage. You must always print on the coated side. Printing on the wrong side will result in most of the ink soaking into the paper fibres rather than sitting on the surface ready for transfer.
So how do you tell which side is which? The coated side is the brighter, whiter side of the paper. Hold a sheet up and compare both sides. One will look slightly brighter and feel marginally smoother. Some sublimation papers also have a very slight curl towards the coated side when left on a flat surface, which can help with identification. Certain brands include a watermark or logo printed on the back (uncoated) side, making it even easier to tell them apart.
If you are ever unsure, do a quick test. Lightly dampen your finger and touch both sides. The coated side will feel slightly tacky compared to the uncoated side, which feels more like regular paper.
Storing Sublimation Paper Correctly
Sublimation paper is sensitive to moisture. The coating is designed to absorb sublimation ink, but it will also absorb moisture from the air if left exposed. Damp paper causes real problems during pressing: the moisture turns to steam under heat, which can cause the ink to blur, shift, or produce a washed-out transfer. In humid conditions, this can ruin entire batches of prints.
The best practice is simple. Keep your sublimation paper in the sealed bag it arrived in when you are not using it. Store it flat on a shelf or in a drawer, away from direct sunlight and any sources of moisture. Do not store it in a garage, shed, or anywhere with fluctuating temperatures and humidity. If you have opened a pack and will not use the rest for a while, place the remaining sheets back in the bag and seal it with tape or a clip.
If you suspect your paper has absorbed some moisture (it may feel slightly limp or produce wavy prints), you can pre-press a sheet in your heat press for 3 to 5 seconds before printing on it. This drives off the moisture and restores the paper to a usable state, though it is always better to store it properly in the first place.
Print Settings That Actually Matter
When printing onto sublimation paper, always use the highest quality print setting your printer offers. This is typically labelled "High Quality" or "Best" in your printer driver settings. Never use Draft mode. Draft mode lays down significantly less ink per pass, which means less dye available to transfer during pressing, resulting in pale and faded prints.
Make sure your paper size and type settings match what you are actually feeding through the printer. If you are using A4 sublimation paper, set the paper size to A4 and the paper type to either "Matte" or "Presentation Matte" if there is no specific sublimation option. These settings control how much ink the printer lays down and how it handles drying time between passes.
For most sublimation work on flat blanks like coasters, phone cases, and plaques, you will need to mirror (flip horizontally) your image before printing. When the paper is placed face down on the blank and pressed, the image reverses, so mirroring beforehand ensures it reads correctly on the finished product. If you are wrapping paper around a mug, mirroring is typically not required.
Cutting and Taping to Blanks
After printing, trim your paper to size but leave at least 5mm of margin beyond the edges of your printed design. This margin serves two purposes: it gives you room for slight alignment adjustments when positioning the paper on the blank, and it helps prevent ink from transferring onto the heat press platen or protective paper, which can then mark future projects.
When taping the paper to your blank, always use heat-resistant tape (polyimide/Kapton tape). Apply strips along all four edges, pulling the paper taut against the surface of the blank. The paper must not move at all during pressing. Even a fraction of a millimetre of movement will cause ghosting, a visible shadow or blur around the edges of your design.
Never use regular sellotape, masking tape, or electrical tape. Regular tapes will melt at sublimation temperatures, leaving sticky residue on your blank and potentially ruining it. Heat-resistant tape peels off cleanly after pressing with no residue.
Quick Reference: Do's and Don'ts
Do print on the coated (brighter, whiter) side. Do store paper in its sealed packaging and keep it dry. Do use the highest quality print setting. Do leave a 5mm margin around your design when cutting. Do use heat-resistant tape on all edges.
Don't use Draft print mode. Don't leave paper exposed to humidity. Don't tape over your printed design (it will leave marks). Don't use regular tape, as it melts and damages blanks. Don't skip mirroring your image when pressing onto flat surfaces.
Getting these fundamentals right from the start will save you wasted blanks and frustration. Sublimation paper is inexpensive compared to the blanks you are transferring onto, so treat it properly and it will do its job perfectly every time.