O.D.: Outside dimensions of a screen printing frame.
Off-contact: The slight gap between the screen and the substrate for improved printability during the printing process.
Opacity: The ability of the ink to cover the underlying color of the substrate.
Open Area: The area of the screen printing stencil that ink passes through. Also used as a measurement in analyzing mesh. The percentage of open area that a mesh has is used to evaluate mesh counts against each other. Typically the more open area a mesh has, the easier it will be to print on a fabric and obtain good opacity.
Overcured: Using excessive heat on the substrate causing the print to crack and fade prematurely. Over curing of plastisol heat transfers will result in transfers that will not adhere properly to the garment.
Overexposed: Using too much light during exposure resulting in a screen that will be difficult to wash out details that have been undercut by excessive light.
Overprinting: A printing technique of printing of one color on top of another one.