NIH provides guidance on the Format Attachments page that is linked through the SF 424.
- Digital images of material such as electron micrographs or gels must only be included within the page limits of the Research Strategy. The maximum size of images to be included should be approximately 1200 X 1500 pixels using 256 colors. Figures must be readable as printed on an 8.5” x 11” page at normal scale.
- Investigators must use image compression such as JPEG or PNG. Do not include figures or photographs as separate attachments either as an Appendix or elsewhere in the application.