What is A4 paper?
The “A4” classification first appeared in the early 20th century in Germany. The system defines three series — A, B, and C — each of which has sizes from zero to 10. The trick is that two A4 sheets will fit the area of one A3 sheet exactly. The same is true of two A3 sheets and one A2 sheet. You can also quickly work out that, for example, four A4 sheets are needed to make up the area of one A2 sheet. A4 is an almost worldwide standard size for letters and documents, but exists in parallel with the “letter” format in the U.S.A. A4 measures 210 x 297 mm (8.3 x 11.7 inches). Letter is slightly wider and shorter at 216 x 279 mm (8.5 x 11.0 inches).
What is acid-free paper?
Various chemicals are used during the paper-making process. If, before the paper is dried and shipped, the acid isn’t washed out fully, the paper will yellow and disintegrate more quickly. Acid-free paper has been properly washed to prolong its usefulness.
How is paper made?
Common office paper is made from trees. The wood is cut into fine chips before being chemically or mechanically pulped — a process which separates the fibers from various resins and other chemicals found in the wood. The resulting fibrous pulp is bleached and rinsed before being pressed into fine sheets and left to dry. These sheets are then cut up to match the required size of paper.
What are the different weights of paper?
The most common weights of paper nowadays are 9, 16, 20, 24, and 32 lbs. These weights refer to the weight of four 500-sheet reams of paper. Most written correspondence uses 20-lb paper, but more-formal documents are often found on 24-lb paper.
Can paper be made of any other substances?
Yes. Paper was once made from papyrus, which is where it got its name. Many different types exist today. Manila paper, for example, is made from Manila hemp; this type of paper is often used for making folders, since it is coarser and more durable than ordinary paper. Paper can also be made with cotton, either pure or mixed to a specific proportion with wood pulp. Adding cotton makes the paper more durable and resistant to environmental conditions than pure wood-pulp paper.