| Term | Definition |
|---|---|
| Offset Printing |
Printing technique that transfers ink from a plate to a blanket to paper instead of directly from plate to paper. |
| Onion Skin |
A specific lightweight type (kind) of paper usually used in the past for air mail. Seldom used today (in the typewriter era). |
| Opacity |
(1) Characteristic of paper or other substrate that prevents printing on one side from showing through the other side. (2) Characteristic of ink that prevents the substrate from showing through. |
| Opaque |
(1) Not transparent. (2) To cover flaws in negative with tape or opaquing paint. Also called block out and spot. |
| Open Prepress Interface |
Hardware and software that link desktop publishing systems with color electronic prepress systems. |
| Outer form |
Form (side of a press sheet) containing images for the first and last pages of the folded signature (its outside pages) as compared to inner form. |
| Outline Halftone |
Halftone in which background has been removed or replaced to isolate or silhouette the main image. Also called knockout halftone and silhouette halftone. |
| Over Run |
Additional printed matter beyond order. Overage policy varies in the printing industry. Advance questions avoid blind knowledge. |
| Overlay |
Layer of material taped to a mechanical, photo or proof. Acetate overlays are used to separate colors by having some type or art on them instead of on the mounting board. Tissue overlays are used to carry instructions about the underlying copy and to protect the base art. |
| Overlay Proof |
Color proof consisting of polyester sheets laid on top of each other with their image in register, as compared to integral proof. Each sheet represents the image to be printed in one color. Also called celluloid proof and layered proof. |
| Overprint |
Printing an image over an area that has already been printed. In printing process colors, one process color is printed over another creating a secondary color, which is a combination of two primary colors. Sometimes in the files that customers send us there will be overprinting issues. Such as type or logos not printing. Customers should be aware that we do not check for this and their overprinting situation must be evaluated before sending the files to us. |