O.S.H.A. Occupational Safety and Health Administration. Government division responsible for monitoring and enforcement of laws pertaining to workplace safety.
OFF-CONTACT A way of screen-printing in which the screen is raised at least 1/8" above the substrate. It is the preferred method for printing nonabsorbent substrates.
OFF-PREMISE SIGN A sign that is not located on the building or property of the business it advertisers. The most common example of an off-premise sign is a billboard.
OGEE In computer graphics, a distortion of an image using an S-shaped curve as one baseline, giving an image a wavy look.
OIL-CANNING Typically used to refer to a metal surface that shows uneven deflection from unsuitable inner structure, poor attachment, or insufficient thickness of face material.
OPAQUE Not clear or translucent; not allowing light to show through.
OPEN CHANNEL LETTER A channel letter with returns that project forward perpendicularly from face of letter, and in which the neon tubing is visible.
ORIGIN The point marking the zero coordinate on the x-, y-, and z-axis. Used as a starting reference by plotters and routers for knife and tool paths.
ORTHO Zero degrees horizontal; a command included in several sign-design software to set an image to a "perfect " horizontal level.
OUTGAS The tendency of a solid or liquid elements in a plastic or composite material (such as particle board) to vaporize over time. Outgassing can occur in some plastics and paints if they have not finished drying, resulting in adhesive failure to anything applied over them. Outgassing also describes the release of impurities in vacuum systems such as neon tubes during processing.
OUTLINE/INLINE In computer graphics, a closed-loop path that copies an original's shape, but is offset by the positive measurement outside the original (outline), or a negative measurement inside the original (inline).
OVERLAP Amount of material either cut or printed in the one panel or tile that duplicates what is done in the previous panel or tile. The overlapping image allows for alignment when assembling and installing a large image.