Here is a general list of things to consider.
Do use:
- Zazzle Embroidery fonts
- Line art
- Lines 4 points or wider
- Crisp outlines (thick outlines are better than thin outlines)
- Colors from the Embroidery Thread Palette
- Solid colors
- Minimal background, cropped to your design
- Smooth edges
- 150ppi or greater
Do not use:
- Complex fills (ex: pattern fills)
- Fine details
- Transparency
- Photography or photorealistic images
- Areas of color smaller than .25" by .25" or multiple colors in small areas
- Lines narrower than 2 points
- Gradients
For more specifics on designing for Zazzle Embroidery, and to review the Zazzle Embroidery Thread Palette, see the Zazzle Embroidery Design Guide.