Print on Demand Artwork Tools

Build a file checklist for each product

Keep a small worksheet for each product, variant, and placement. Write down the provider’s file format, physical dimensions or required pixels, safe area, and color instructions. Save the template version or date you consulted. When the same design has a mug wrap and a wall print, keep separate outputs with names that identify the product so an upload does not silently take the wrong version.

Worked example for two wall-art listings

Suppose you have a 4,800 × 6,000 pixel portrait with a 4:5 shape. A 16 × 20 inch version uses the whole image at 300 PPI. A 12 × 18 inch version uses a different shape. When the image fills that rectangle, the 6,000-pixel height yields roughly 333.33 PPI. At that scale, the layout uses about 4,000 width pixels. A crop removes 800 of 4,800 width pixels, about 16.67% of the original image area.

Preview the crop before using the same source on the new product. A centered crop may remove signing details or lettering close to the edges. Reposition the artwork, use a border, or prepare a separate design if the crop harms the composition. A large image can still be wrong for a product when its shape does not match.

Validate the actual export, mockup and sample

Open each final file after exporting. Check pixel dimensions, orientation, white or transparent background, and whether your export retained the requested profile. Then review the product preview with the correct variant selected. Check any visible gaps or seam crossings before saving the listing. If the provider’s upload scales an image to fit, note the resulting placement size rather than assuming the original design dimensions were used.

When color, fine type, or edge placement matters, inspect a production sample. Save the approved export beside the notes from the sample. When artwork changes, recheck each variant affected by the revision. See Printful’s file guidance for one provider’s checklist, then follow your own product specifications.

Common upload mistakes

A transparent canvas can hide the fact that the artwork itself occupies a smaller area. A print preview is useful for placement but may not reveal a soft raster logo. Keep product labels and export names consistent so a 12 × 18 file cannot be mistaken for the 16 × 20 version.

For a larger catalog, make a contact sheet of the submitted versions so you can spot a missing placement or a repeated export. Name each preview with the product and dimensions and keep a note of which revision was approved. When a customer reports an issue on one variation, check that exact file and its printed size first. A single problem may come from placement on that particular SKU rather than from the source design shared by the whole listing. Keep the original composition available for replacement exports.

Frequently asked questions