Media Facts, Hints and Tips for Media on Océ CPS Systems

CapturePrinting performance—and as a result the quality of finished documents—is strongly related to the media used. For this reason, media selection and use play an important role in meeting the everincreasing quality demands on professional colour printing.
This white paper provides an introduction to media properties and selection criteria, together with some tips in relation to the Océ CPS series colour printers.

This white paper is part of a set of white papers to explain the Océ technologies and applications. See also the white paper ‘Direct Imaging colour printing’.

1 Basic properties of paper
In the process of making paper, a lot of variables are used to produce specific types of paper. Adjusting these variables results in different properties of the paper that is produced.

1.1 Grain direction
The grain direction of a paper is the direction in which most of the fibres lie. During the papermaking process, the majority of the paper fibres are aligned in parallel. Depending on how the paper is cut to its final size, it will be either long grain (with the grain parallel to the longer dimension of the paper), or short grain (with the grain parallel to the shorter dimension of the paper). The standard is long grain for A4 and short grain for A3 paper. This is also the best grain direction for the paper path of the Océ CPS series printers when using A4 and A3 paper.

1.2 Stiffness
Stiffness refers to the rigidity, or bending resistance, of paper. Thicker papers are usually stiffer. In general, paper with a low gram weight is more likely to ‘bunch up’ or wrinkle in a printer, causing jams and misfeeds. Runnability can usually be improved by feeding lightweight paper with the grain direction the same as the feed direction. This reduces the chance of wrinkling because of a higher stiffness. When feeding heavier paper, the grain direction should be opposite to the feed direction. This results in lower stiffness and better runnability.

1.3 Weight/thickness
In most paper specifications, weight is a very important consideration. Heavier sheets are often thicker because they contain more fibres. These papers may be too thick or rigid to pass through the paper path of certain printers. They may also crack or blister when folded (even if scored).