Decide on the intended print size first
A PNG extension does not tell you how large a design can be printed clearly. What matters is the available pixel count, the intended print width and the printer’s requirements. Open the properties of the file you actually downloaded. The generator’s quality setting is not a measurement of print size or resolution.
Print width in cm = pixel width ÷ desired ppi × 2.54 gives you a useful calculation. The examples below use 300 pixels per inch. This is an example setting, not a universal minimum for every printing process.
| Pixel width | Print width |
|---|---|
| 1,024 px | about 8.7 cm |
| 1,536 px | about 13.0 cm |
| 3,000 px | 25.4 cm |
Printing 30 cm wide at 300 ppi requires roughly 3,543 pixels. Changing the ppi value in file properties does not create more detail. Upscaling adds pixels but can also change outlines or lettering. Always inspect the final result and check the printer’s specifications.
Check actual transparency
Open the PNG in an editor that displays transparency as a checkerboard. Place a white, black and brightly coloured layer behind it in turn. This exposes light halos, leftover backgrounds and partially transparent marks. The checkerboard itself must not be saved as part of the artwork.
Pay particular attention to the spaces inside letters, fine branches, fur edges and gaps between elements. A transparent rectangle around the artwork does not prove those inner spaces are clean. Remove isolated pixels far outside the design as well: they can affect automatic centring or size calculations in a product editor.
Preview the actual garment colour
A black outline can disappear on a black shirt. Cream lettering can lack contrast on white fabric. Inspect the design on every colour you intend to offer. If it only works on one colour, limit the product selection or create a deliberate second version of the artwork.
Zoom in to find defects, then view the design at its intended output size to judge readability. Details that are only visible when zoomed in contribute little when someone wears the shirt. A screen preview cannot reliably reproduce fabric texture, ink coverage or any white underbase used in printing.
Final checks before upload
- Wording, lettering and illustration details are correct.
- Pixel dimensions match the planned print area and the provider’s requirements.
- Transparency and edges have been checked on light and dark backgrounds.
- Nothing is cropped, and large empty margins do not unnecessarily shrink the artwork.
- The final exported file has been reopened and inspected.
Keep the original and edited versions separate, for example bees_original.png and bees_dark-shirt_v2.png. Before selling, a physical sample helps you judge size, placement and the actual print. A file being accepted by the provider is not proof of print quality.