Here are the artwork requirements for print on demand services, as inferred from multiple resources:Size: The size of your artwork file should match the print area of the product you're designing. This will depend on the specifics of the product, so it's recommended to check each product's size guide on the print on demand platform you are using.
DPI (dots per inch): Generally, a DPI of 300 is recommended for optimal print quality. This would mean that for each inch of the printed area, your design has 300 dots (or pixels) of detail. However, insufficient DPI can lead to blurred or pixelated prints.
Format: Print-on-demand artwork should ideally be in a lossless format, such as PNG or TIFF. These formats preserve all the original data of the image, ensuring the best visual results when printed. JPEGs can also be used but tend to lose quality each time they are saved.
Color Mode: The artwork's color mode should preferably be set to RGB. Even though prints are typically done in CMYK color mode, RGB has a wider range of colors and most print-on-demand platforms automatically convert RGB to CMYK.
Please note that it's critical to check the specific requirements of the print-on-demand service you're utilizing, as these can vary.