How to Print a Phone Case Using a Sublimation Printer
Custom phone cases are one of the easiest sublimation products to get started with. They press quickly, the blanks are affordable, and the finished results look professional. Whether you're making one for yourself or selling them as part of a small business, the process is straightforward once you understand the basics.
The most important thing to know upfront is that you can't sublimate onto just any phone case. The case needs a polyester or polymer coating on the surface where your design will be printed. This is usually the back panel, and sometimes the sides as well on wrap-around cases. Plain silicone, rubber, or uncoated plastic cases won't hold sublimation dye. You need blanks that are specifically designed for sublimation, like the ones in our sublimation phone cases range.
Getting Your Template Right
Phone case dimensions vary significantly between models. An iPhone 16 Pro Max case has different measurements to a Samsung Galaxy S24, which is different again to a Google Pixel 9. You can't use one template for everything. Each phone model has its own case shape, camera cutout positions, and printable area.
Most blank suppliers provide downloadable templates for each phone model they stock. These templates show the exact printable area, camera and button cutouts, and any margins you need to allow for. Start by downloading the correct template for your specific case and phone model, then build your design within it. Trying to guess the dimensions or resize a generic design to fit will almost always result in misaligned prints, covered camera holes, or artwork that wraps awkwardly around the edges.
If you're designing cases for the latest iPhones, we've put together a dedicated guide covering template setup for those models: how to design sublimation templates for iPhone 16 series cases.
Designing Your Phone Case
Open your template in your design software. Photoshop, Affinity Designer, and CorelDRAW are all solid choices. Canva can work for simpler designs, though it's less precise with template alignment. Whichever tool you use, set your document to 300 DPI as a minimum. Phone cases are small products that people hold close to their face, so any lack of sharpness or pixelation will be immediately obvious.
Place your artwork within the printable area defined by the template. Pay attention to camera cutouts and any areas that wrap around the case edges. Key elements like text and faces should sit well within the safe zone, away from the edges where slight misalignment during pressing could crop them awkwardly.
Bold colours and high-contrast designs work particularly well on phone cases. Fine gradients and very subtle tonal shifts can sometimes look slightly different on the polymer coating compared to how they appear on screen, so designs with strong colour contrast tend to give the most consistent results.
Printing the Transfer
Once your design is finalised, mirror the image. This is essential with sublimation printing. The printed side of the transfer paper goes face-down onto the case, so if you don't mirror the image, any text or directional elements will appear reversed on the finished product.
Print onto sublimation paper using sublimation ink. Use your printer's highest quality setting and make sure you're printing at the correct size. It's worth doing a test print on plain paper first and holding it up against the case to check alignment before using your sublimation paper.
Pressing the Case
Phone cases can be pressed using either a standard flat heat press or a 3D vacuum press. Which one you need depends on the case design.
Flat-back cases work well in a regular flat press. Position your printed transfer face-down on the back of the case, centred carefully, and secure it with heat-resistant tape on the edges. Make sure the paper is flat against the surface with no wrinkles or lifted corners. Set your press to 190 degrees Celsius, press for 50-60 seconds at medium pressure, then remove.
Curved cases or cases where you want the design to wrap around the sides need a 3D vacuum press (sometimes called a 3D sublimation oven). These use a combination of heat and vacuum pressure to pull the transfer paper tight against all the contours of the case. The settings are similar: around 190 degrees Celsius for 50-60 seconds, though you should follow the specific instructions for your vacuum press model as they can vary.
Once pressing is complete, carefully peel the transfer paper while the case is still warm. Removing it while warm gives a cleaner release than waiting for it to cool completely. Handle the case with care as it will be hot.
Tips for Better Results
Alignment is the biggest challenge with phone cases. The printable area is small, and even a couple of millimetres of misalignment is visible. Take your time taping the transfer to the case. Some people find it helpful to use a lightbox or hold the case and transfer up to a window to check positioning before taping.
If you're pressing multiple cases in a batch, make sure each transfer is taped individually and securely. Phone cases are light, and transfers can shift during handling if they're only loosely attached.
Colour consistency between batches depends on your ink levels and printer maintenance. If you notice colours shifting or becoming less vivid over time, run a nozzle check and make sure your ink tanks are topped up. Sublimation ink that sits unused in the printer for long periods can cause clogged nozzles, which shows up as banding or missing colours in your prints.
Clean your heat press platen between presses if you're switching between different designs. Sublimation dye can off-gas onto the press surface and ghost onto the next item if the platen isn't clean. A quick wipe with a lint-free cloth between presses prevents this.
Selling Custom Phone Cases
If you're looking at phone cases as a product to sell, keep your template library organised by phone model and updated as new models release. Customer satisfaction depends heavily on the print being correctly sized and aligned for their specific phone, so accuracy matters more than speed. Offering a few popular models well is better than trying to cover every phone on the market with poorly fitting templates.
Phone cases are a high-volume, low-cost product with good margins. The blanks are inexpensive, pressing is quick, and the perceived value to customers is higher than the production cost. Combined with the fact that almost everyone has a phone, it's a reliable product line for any sublimation business.