Venky Designs — Design production specs for print | venkydesigns.com
Hand the printer a press-ready PDF, keep AI, EPS or SVG for anything that must scale, use TIFF or PNG for lossless raster images, and treat JPEG as the format of last resort.
A press-ready PDF is the standard container because it holds everything the pressroom needs in one file: final trim size, bleed, trim marks, CMYK color and fonts that are embedded or converted to outlines. What goes into the PDF still has to meet the numbers — 300 DPI effective resolution, 3 mm bleed, ink coverage under the cap — but the format itself carries them intact.
Vector formats (AI, EPS, SVG) store geometry instead of pixels, so the same logo scales from a 20 mm business card to a 2 m banner with no quality loss. That makes vector the only acceptable way to supply logos and type-driven artwork; raster art, by contrast, must be supplied at 300 DPI of its final size and cannot be stretched past it.
On narrow screens, swipe or scroll the plate sideways.
Among raster formats the dividing line is compression. JPEG throws image data away to shrink the file, typically saving at quality 60-80, and it discards more data at every save — a JPEG edited and re-saved a dozen times carries a dozen rounds of loss. PNG and TIFF stay lossless: PNG preserves transparency for screen work, TIFF carries full-quality raster images for print.
Screens change the arithmetic. Anything that stays on a monitor or phone renders at 72-96 PPI, so web and interface graphics are exported as PNG, SVG or JPEG at pixel dimensions matched to their display size rather than to any DPI figure.
Two rules apply inside every container, whatever its extension: all fonts embedded or converted to outlines before export, and no hairline thinner than 0.25 pt, because finer rules can drop out on press. The resolution math behind the 300 DPI requirement is worked through on the homepage, the color conversion on the RGB vs CMYK Color Modes page, and the ordered final pass on the Print Preflight Checklist page.
Further reading