I see this come up over and over again. So, I thought it was time to sit down and explain how it works so it's easier to understand.
Can you sublimate on black shirts? Can you sublimate on colored shirts? The short answer, yes. You absolutely can, but your results will vary greatly. Sublimation is a dye process and doesn't print white. I mean, if you think about it, there really isn't a way to dye something white anyway. You can bleach it, but thats totally different. So if you want to use a darker shirt, or a black shirt, technically it WILL dye it, but you wont see it very well, if at all. The best way I have found to explain it to my customers is this: Picture the dyes in your design are Crayola Markers, and the shirt is construction paper. If you colored on black paper with markers, nothing will show up. If you color on yellow paper with a pink marker it will look orange. And so on.
Can you sublimate on 50% polyester shirts? The percentage of polyester plays a huge factor as well. The chemical properties of the dyes require you to have polyester in the shirt. The higher percentage of polyester, the more vivid the colors will be. Basically, if you use a shirt that is only 50% polyester, only HALF of the dye will transfer. Sometimes it doesn't look too bad, but if any extra color did transfer onto the shirt, the reminder of that HALF will wash out the first time you wash the shirt. Only half of the ink will be permanent.
In an attempt to give you all a visual, I put together a graphic with a simple color wheel to show you how different colors will work on different shirts and different polyester counts. This is only an estimate of course, but should give you pretty good idea of how it will turn out. Especially after you wash it for the first time. I even made a printable PDF version in case you wanted to save and/or print it for easy reference! Or you can download the graphic by clicking the image below.
I hope this helps explain things! Sometimes all this sublimation stuff can get pretty confusing and doesn't get thoroughly explained very well. If I missed something, or you still have questions, please let me know!