Beware of JPG (jpeg)

JPG is a “lossy” compression format. When you save a JPG file, there is a quality setting ranging from “high quality” to “low quality”. This determines the amount of compression added to the image. The more compression, the more colour detail is lost from the image. A quality setting of “high” will discard the least amount of data. Each time you open and re-save a JPG, more colour information is lost, resulting in lower quality print.

Formats for Photographic and Bitmap Images

Save all photographs and bitmap images as flattened TIFF files. If the native application your print file was created in supports PSD files, render the text layers to pixels (rasterize layer) or supply the fonts.

Digital Camera Files

For high resolution photo reproduction, set the camera to the “high” quality setting. After the image is transferred to the computer, call up the file in an image editing program such as Photoshop. The image size should be about 30 inches by 20 inches with the resolution set at 72 ppi. Re-sample to your desired finished print size, changing the resolution to 300 ppi, and save the image(s) to TIFF.