Small holes through paper which are made on a folding machine to facilitate the folding of paper. Often used along the edge of a business reply card to ease removal of the card from the printed piece. A proof pulled off the printing press as the job is being printed. Color density can be fine-tuned on press. A client goes to the printing vendor's shop to view this kind of proof.
Process color is necessary to reproduce color photography.
Four screens, one for each color, are printed over each other sequentially to create the range of tones in full color. Percentages of these four primaries can be used to build a CMYK equivalent to a Pantone color, however, not all colors can be matched exactly. Scans must have adequate resolution to reproduce with clarity. It's useful to know that images prepared for Internet use do not contain adequate resolution for printing. These files are removed and replaced with High Resolution Scans with a correct level of resolution for printing.