Will my design work on a black shirt and a white shirt?
Only if no important part of it is the same color as the shirt. White fills vanish on a white shirt, and black fills vanish on a black one.
- Look at both previews. The free preview shows the design on a dark and on a light shirt color.
- Find what disappears. Letters, outlines or shapes that match the shirt color are gone on that shirt.
- Decide. Sell it on the shirt colors it suits, or make a second version for the others.

Check your own design on both, free.Upload your design
Fixes
An outline in a contrasting color keeps a pale fill readable on a pale shirt. Or keep two files, one per shirt color.
What the file does not do
A transparent PNG has no shirt color in it. The same file prints on any shirt; whether it reads is up to the design.
Operated by Brilliant Design Ltd.