07 Nov Everything you could ever want to know about paper
ISO Paper Size & Dimensions Chart
Paper Size & Weight
International Metric Paper Sizes – ISO Standard
A0 to A7 paper size with dimensions in centimetres and inches.
The term GSM refers to the weight of the paper, relating to an area of paper that remains constant, irrespective of sheet size, expressed as Grams per Square Metre. As a starting point, standard printer paper is generally around 80gsm.
The basis weight of a paper is the designated fixed weight of 500 sheets, measured in pounds, in that paper’s basic sheet size. in thousandth of an inch. This measurement is taken with a micro meter.
Paper Stock Considerations
There are many things to consider when choosing the grade, finish, colour, thickness and grain of the paper you use for a project. The paper you use will support the design concept and style of the piece so ensure that you give it due consideration.
Opacity is the lack of transparency that allows a sheet to conceal print on its reverse side and it’s greatly influenced by the paper’s basis weight, brightness, type of fibre and filler.
Aside from its aesthetic importance, paper brightness affects the legibility and contrast of printing.
Finish relates to a paper stock’s level of smoothness. Typical uncoated paper finishes are: antique, eggshell, vellum, smooth and lustre. These are classed together because they can be produced in the machine. Additional smoothness can be obtained by a process called “supercalendering” and also coating further improves the finish and smoothness.
The smoothness is a measure of paper surface irregularities. The property affects many end uses, particularly the appearance of printing. Some typical smoothness values are: 10 -30 for very smooth paper; 100 -150 for smooth paper and 200 -250 for vellum paper.
The direction in which most fibres of a sheet of paper lie is called the grain direction. As paper is formed, the fibres move forward on the paper machine at high speeds, aligning the fibres in the direction of the movement and creating the grain. At the same time, the machine shakes the slurry of fibres from side to side, so that the fibres crisscross. This crisscrossing creates a web of fibres, and gives the paper strength in both directions, while maintaining a predominant grain direction.
How Grain Affects Strength
Making a tear in a sheet of paper along the grain is easier than tearing a sheet across the grain. Tearing with the grain pulls fibres apart from each other, while tearing across the grain tugs at whole fibres, which have a greater inherent bond. Folding with the grain is also easier than folding across the grain. Folding against the grain may cause the paper to crack or buckle if it has not been scored first. Generally, lightweight paper does not need to be scored. It is usually best to score heavier paper stocks prior to folding to ensure the paper doesn’t crack. Recycled paper is less apt to crack when folded against the grain, because the fibres are shorter and the bond not as strong.
Read more about paper here in our handy guide on paper folding