An image that looks sharp on a phone may contain too few pixels for a large printed graphic. Judge raster artwork at the size it will be printed, rather than by its file size or how polished it looks on a small screen.
Start with pixel dimensions
For a raster image, divide its pixel width by its intended printed width in inches to find its effective pixels per inch. A 3,000-pixel-wide image printed 30 inches wide provides 100 pixels per inch. Printed 60 inches wide, the same image provides 50. This calculation describes the source detail; it is not a universal quality target.
The appropriate resolution depends on the product, artwork and viewing distance. Ask for the requirements for the exact material and final dimensions. Changing a resolution label in an image editor without adding real image detail does not recover a sharper original.
Keep logos and text clear
Use original vector artwork for logos and shapes when available. Vector paths can be resized cleanly, but a vector file can still contain low-resolution photographs. Review any embedded images separately. If you only have a small logo screenshot, ask about vectorization rather than repeatedly enlarging it.
Review before export
Check the final proportions, spelling and placement of important elements. Keep an editable source file, and label the exported version with its dimensions. Open the export to confirm that fonts, transparency and images appear as intended.
Read the artwork guidelines for the upload workflow. If you are uncertain, send the product link, print dimensions and original file information through an artwork file review request.