Set Document Color Mode to RGB or CMYK
All critical colors should be Pantone® Solid Coated – In Illustrator from your “swatch window” choose Open Swatch Library/ Color Books/ Pantone+ Solid Coated to select. Supply a color proof or sample if matching non-pantone colors is critical.
Convert all fonts to outlines – in illustrator: from the Type menu select Create Outlines.
Ensure that all raster images are at least 100dpi at print size
Flatten all transparencies – especially InDesign and Illustrator files
Save your file as uncompressed .eps, .pdf, or .tif
Large files can be created at scale: 1/2, 1/4, 1/10, etc. Watch your image resolution (dpi) when scaling!