Images for press:
RASTER images (working in Photoshop):
- Ask for original images.
- Request .tiff, .raw, or .psd files. Generally avoid .jpg, .png, and .gif. files. Original .jpg straight from the camera usually does fine if it is not compressed too much. A very compressed .jpg results in artifacts. Try to get original image. Never edit and re-save jpg images, every time you do you are adding more artifacts.
- Review for quality.
- Image Size Rez min: 250dpi + at dimension(s) in inches/cm it will need to print.
- Typically used color profiles (check with your printer, some offer custom profiles for their presses):
- U.S. Web Coated (SWOP) v2 for Magazines
- ISOnewspaper30v4GCR4 for NYTimes newsprint
- US Newsprint (SNAP 2007) for Generic newsprint
- U.S. Sheetfed Coated (SWOP) v2 for packaging and brochures
- U.S. Sheetfed Uncoated (SWOP) v2 for packaging and brochures
- Total ink coverage: Using the Info palette in Photoshop select panel options and Total Ink. Check denser areas of image. Add C+M+Y+K, for Newsprint and if the sum is more than 240, then it may be too much ink. Magazine paper can handle 280-300 or even higher if it is high quality. Usually applying a color profile as a final step will fix these issues. Check with your printer for their press specs.
- Do NOT multiply too many layers in PS … this can result in creating colors that are unprintable (see 8). If you do work this way, then as a final step, create a final flattened file and merge the layers, then apply the appropriate color profile.
- Change images with 16 bits/channel down to 8 before sending to press.
- Adjust colors using Levels or Curves in adjustment Layers.
- Avoid using Brightness/Contrast … Levels or Curves are far superior for adjusting contrast. They can also be used to adjust colors channels separately.
- The major issues with Newsprint involve the lower end of mid tones … simply making whiter whites and darker darks does not make it better.
VECTOR images (working in Illustrator):
- Unless printing SPOT colors, convert them to CMYK.
- Convert RGB to CMYK.
- Be sure white is NOT set to overprint.
- Colors can be set to overprint if you want that effect of transparency. Also edges of shapes can be set to overprint for trapping.
- If printing BW, be sure that black is NOT a Rich Black (built of CMYK).
- Be sure there are no embedded or raster images.