The ideal DPI (dots per inch) for digital printing graphics can vary depending on the specific printing method, the size of the printed piece, and the viewing distance. Generally, higher DPI values result in better print quality, but they also increase file size and processing requirements. Here are some guidelines for common printing scenarios:

1. Commercial Offset Printing: For high-quality offset printing, a DPI of 300 is often considered standard. This resolution ensures crisp and clear prints for most graphics and images.
2. Digital Inkjet Printing: Inkjet printers have advanced significantly and can produce good results at lower DPIs. A range of 150 to 300 DPI is typically sufficient for most inkjet printing applications.
3. Large Format Printing: For large banners, posters, or other large-scale prints that are viewed from a distance, you can get away with lower DPI settings. Often, a DPI of 100 to 150 is sufficient.
4. Desktop Printers: For office or home desktop printers, using 300 DPI is a safe bet for most print jobs.

Remember that the viewing distance plays a crucial role. If the printed piece will be viewed up close, such as brochures or magazines, a higher DPI will ensure sharper details. However, if the printed piece will be viewed from a distance, like billboards, you can use a lower DPI.

Additionally, consider using the appropriate color profile (CMYK for printing) and saving the graphics in a format suitable for printing, such as TIFF or PDF with embedded fonts and images.

Always check with your printing provider to see if they have specific requirements or recommendations for DPI settings to ensure the best results for your particular project.