A common question we’re often asked is what sorts of things can be sublimated. The questions can range from “Can I use sublimation on a dark shirt?” to “Are the mugs people use for sublimation special?” to “I found this piece of barn wood/antique tray/glass bowl, can I sublimate it?”. The common theme of all these questions is that people aren’t quite sure what products can be sublimated and which can’t or aren’t suitable, and they’re looking for some guidance. Basically, when it comes to determining whether or not something can be sublimated, it’s about three things:
Thing 1: Color
As much as we’d all like it to exist, there is no white ink option for sublimation. This means there is no way to put a white underbase down. A white underbase allows for printing of colors on dark shirts, since the inks actually print on the underbase and not the shirt. The lack of a white ink option to lay down as an underbase means that sublimation must be done on light colors. Keep in mind that the ink dyes the fabric when set with heat, so using any color shirt other than white will change the color of the ink to some degree.
While there is currently no option for direct sublimation, printing the transfer directly on the shirt, when it comes to dark colors, there are options for printing a sublimatable material and then transferring that to the shirt. Our fabric sheets might work in some cases. There are other thinner options for things like t-shirts that can also work. There are also a few spray coating options out there that claim to perform the function of a underbase. Do keep in mind, however, that these options are more in the nature of a transfer or a carrier and will have a hand and feel different that actual sublimation would.
Thing 2: Coating
If you’re working with a 100% polyester light-colored t-shirt, coating doesn’t matter and isn’t needed. Where coating is vital is when you’re dealing with hard goods. Any hard good, a mug, bag tag, key chain etc. must be coated with a poly based coating that works with the sublimation ink. With this coating the ink will not transfer well and will certainly not be permanent.
There are two options for getting a coated hard good. One option is to buy blank items that are already coated, which means you can simply print your sublimation transfer and proceed to sublimate the item. The other option is to purchase a sublimation coating spray or liquid and coat the item to be sublimated yourself. While the do it yourself coatings expand the range of items which can be printed through sublimation, getting the coating on evenly can be tricky. If the DIY coating drips or is uneven, then the finished print will have issues as well.
At EnMart, we tend to recommend buying pre-coated items, simply because we’ve seen how tricky it can be to get the sprays or liquids on evenly. The advantage of a pre-coated item is that it was coated in a factory, by specialized equipment designed for that job. While it isn’t always the case, pre-coated items are more likely to have an even coating and be free of issues that an uneven coating can cause.
Think 3: Heat and Pressure
An essential ingredient for sublimation is heat. Without heat, the ink won’t sublimate properly and the print won’t transfer. Anything that is going to be sublimated must be able to stand up to the heat of a heat press or a convection oven, most likely temperatures somewhere between 350 and 400 degrees. Anything that would melt or warp at those temperatures is not suitable. That’s why sublimation isn’t often done on plastic items, they melt at the temperatures that are required.
Pressure is another essential ingredient in the sublimation process. When an item, like a mug, is sublimated in a convection oven, the transfer is held to the mug with a wrap. The wrap is usually as silicone band which latches around the item and holds the sublimation transfer securely to it. A heat press, which works by latching closed around the item and providing heat also applies pressure to the substrate. Anything that is thin or fragile will not stand up to the pressure involved and may shatter.