Opacity refers to the property of paper which obstructs the passage of light and show-through of printing. This characteristic is expressed as the percentage of visible light that does not pass through a sheet of paper. For example, 98% opacity means that 98% of the light can not pass through the sheet, and is absorbed in or reflected by the paper’s surface. Low opacity means the paper will have more show-through, such as tracing paper. High opacity means there will be less s

The paper you use is a critical factor in the appearance of your printed projects. For most of our products, Castle Press has suggested paper options to those most popular for the usage. There are hundreds of different paper brands, colors and weights available depending on the budget for your project. About Paper Options There are three attributes that differentiate papers from one another: finish, weight and opacity. Finish Finish refers to the texture, feel and appearance

Standard Paper Sizes and Specifications for stationery, marketing collateral, commercial envelopes, catalogs, and more