Try this little example.
“Little Things Club” combines an original star, a circle and two editable text layers. At 10 × 12 inches, the PNG is 3000 × 3600 pixels. Switch to centimeters to see 25.4 × 30.48 cm; the output stays the same.
A 600-pixel image placed 4 inches wide has 150 effective DPI. Exporting at 300 DPI adds pixels, not detail. Shrink its printed size or use a larger original.
Useful limits, honestly.
The shirt preview is an illustration, not a size chart or professional proof. Screen colors may differ from fabric and ink. No printer-specific color matching, guaranteed fit or print quality. White ink, transparency and printable areas vary by service.
PNG/JPEG only; image proportions stay locked. JPEG backgrounds remain visible. V1 supports single-line text, simple shapes and up to 20 layers. The included shapes are original; the bundled Liberation Sans font is SIL Open Font licensed. Your own artwork retains its own rights and restrictions.