In Europe everyone from a school child to your granny knows that you buy A4 paper for your printer at home. It measures 297 x 210 mm every time you buy it because it's a standardised size whether or not you buy it in the UK, Germany or Portugal.
Some people know that A5 is half the size of A4 and often used by card makers and A3 (twice the size of A4) is a popular photographic printing size.
Professional printers use B size paper. These are slightly larger than A sizes which allows for the paper to be trimmed down to an A size after it's been printed.
However ordering paper in the old days wasn't quite so simple...
England had its own sizes as did France, Germany and Holland. Instead of an A or B designation they had names. Even more confusingly these names might not even guarantee that you'd get exactly the same size.
Variations in sheet size were common in hand production. Also, some mills measured their paper from the outside edge of each deckle and some from the inside which could account for up to 1/2 inch difference. Grades for printing were traditionally made larger than for writing, hence a further variation of 1/4 - 1/2 inch.
Here at VPCo our business is buying and selling vintage and antique paper and one of the joys of this is identifying the various sizes which can often inform us what purpose the paper might have been made for. For example, a paper in Post size was almost certainly made for correspondence. It can be identified by its size and often via its watermark; an image of a post horn which may have signified an urgency in delivery.
Many artists around the world will be used to ordering Imperial sized paper - it's 56 x 76 cm or 22 x 30 inches. In the US it's often called Full Sheet rather than Imperial. Some artists will be familiar with Elephant or Double Elephant and of course Foolscap is a well known size. Perhaps its not so well know that for many years Foolscap paper contained a watermark of hatted Jester or a Fool's Cap.
THE BRITISH AND US CUSTOMARY SYSTEM
A system in which standard sizes were formulated was accepted in Britain in 1836.
Called The Imperial System, its object was to assist the production of a uniform result, thus making it possible to save time, energy and expenditure in manufacture, and allowing the papermaking trade to make a better-informed judgement on quality.
A few years earlier, a similar standardization of traditional British units had taken place in the United States, resulting today in what is known as the U.S customary system.
In the world of fine paper today, the term 'Imperial' is still applied to traditional sizes and linked weights of the premetrication era.
ENGLISH PAPER SIZES
Antiquarian - 51 x 55 in, 787 x 1346 mm
One of the largest drawing papers made by hand in Europe, its size has varied over time between 36 x 54 and 29 x 52 in. It was first made in England, in Kent, by James Whatman in 1773: the moulds for these huge sheets were hoisted on a lifting device called "The Contrivance", with six to eight men required in the dipping and couching processes.
Antiquarian was a popular size for creating architectural and ship building plans.
Atlas - 26 x 34 in, 660 x 864 mm
Extra Large Atlas - 27 x 35 in, 686 x 889 mm
A large size of drawing paper, originally developed for the printing of maps and atlases from engraved plates
Cartridge - 21 x 26 in, 534 x 661 mm
Traditionally a size for wrapping and drawing papers. Originally derived from the Italian cartoccio, paper (carta) for wrapping up a charge of powder.
Colombier - 24 x 34 1/4 in, 597 x 876 mm
This size was standard in England, although foreign equivalents vary. It was popular with American papermakers in Pennsylvania. The original watermark of a dovecote, after which it was named, was a play on the name of the Auvergnat papermaker Colombier.
Crown - 15 x 20 in, 381 x 508 mm
Double Crown - 20 x 30 in, 508 x 762 mm
Quad Crown - 30 x 40 in, 762 x 1016 mm
A printmaking size which has varied historically. The name, from the French demi, indicates that it was originally derived by folding a large sheet in half (possibly a Colombier drawing paper, or an Imperial writing paper). Demy traditionally carried the fleur-de-lys within a shield watermark.
Eagle - 28 1/4 x 42 in, 730 x 1067 mm
An old standard size of drawing paper known as early as 1300, which took its name from a watermark of an eagle.
Elephant - 20 x 27 in, 508 x 686 mm
Double Elephant - 27 x 40 in, 686 x 1016 mm
A sheet also name after its watermark. Double Elephant is also called Grand Eagle. The variations are still particularly wide in the largest sheet of this size.
Emperor - 48 x 72 in, 1219 x 1829 mm
This name has been used for a size of notepaper but more commonly refers to a writing or drawing size. In the US it often means 40 x 60 in (1016 x 1520 mm)
Foolscap - 13 1/2 x 17 in, 343 x 432 mm
Double Foolscap - 17 x 27 in, 432 x 686 mm
Quad Foolscap - 27 x 34 in, 686 x 864 mm
A size for writing drawing and printing which could vary by 2 or 3 inches from the standard given above. The name comes from the watermark of a jester's head (with the cap and bells), introduced to Britain in the mid-16th century; this was replaced in the 18th century by the Britannia watermark.
Hand - 16 x 22 in, 406 x 559 mm
Royal Hand - 20 x 25 in, 508 x 635 mm
The name derives from the watermark, traditionally a hand or glove, dating back to the 16th century.
Imperial - 22 x 30 in, 559 x 762 mm
Large Imperial - 22 x 32 in, 559 x 813 mm
Half Imperial - 15 x 22 in, 381 x 559 mm
Double Imperial - 30 x 44 in, 762 x 1118 mm
A popular size traditionally for writing and printing papers, in common use today.
Medium - 18 x 23 in, 457 x 584 mm
Double Medium - 23 x 36 in, 584 x 914 mm
Quad Medium - 36 x 46 in, 914 x 1168 mm
This size occasionally today watermarked with the traditional fleur-de-lys
Post - 15 x 19 in, 387 x 489 mm
Large Post - 16 1/2 x 21 in, 419 x 533 mm
Double Post - 21 x 33 in, 533 x 838 mm
The name derives from the watermark of a post horn, first used in the 14th century
Pott - 12 x 15 1/2 in, 317 x 394 mm
This is the smallest handmade size, used for writing and drawing papers. The earliest Pott watermark illustrates a pot or chalice divided into compartments for holding food and drink. Foreign equivalents vary.
Royal - 20 x 25 in, 508 x 635 mm
Super Royal - 20 x 28 in, 508 x 711 mm
Double Royal - 25 x 40 in, 635 x 1016 mm
Quad Royal - 40 x 50 in, 1016 x 1270 mm
A size for drawing, writing and wrapping, formerly watemarked with an ornamental shield surmounted by a fleur-de-lys.
In Europe, thanks to the metric system we measure the weight of a sheet of paper in gsm or grams per square meter.
This means that we know, no matter how large a sheet of paper is, if it weighs 90gsm or so it's a suitable weight for printing documents on an inkjet printer. A 130gsm paper might be considered a luxury weight for printing or writing letters and 300gsm a great weight for printmaking or watercolour.
In the Imperial system, before metrication and still used in the US, the basis of weight of paper is expressed in terms of the weight of a ream (now 500 sheets although in the past it might be 472, 480 or 516 sheets) of a particular size.
Thus if 500 sheets of the size called Imperial ( 22 x 30 in) when dry weigh approximately 140lb, the paper is termed 'Imperial 140lb'. This principle can give rise to confusion because sheets appear to weigh more in different sizes e.g. Double Elephant 246lb has the same basis weight as Royal 106lb.
To convert Imperial weights for various sizes of sheet to gsm, multiply the weight in pounds (lb) per ream by the following factors:
Double Crown 2.34, Demy 3.27, Imperial 2.08, Medium 3.4, Large Post 4.06, Royal 2.81
To convert gsm into the nearest equivalent in pounds per ream, divide the weight in gsm by the same factors - thus 150gsm is equivalent to Imperial 72lb.
FRENCH TRADITIONAL PAPER SIZES
Carre* - 17 3/4 x 22 in, 450 x 560 mm
Cloche - 11 7/8 x 15 3/4 in, 300 x 400 mm
Colombier - 24 3/4 x 35 1/2 in, 630 x 900 mm
Couronne* - 14 1/8 x 17 3/4 in, 360 x 450 mm
Ecolier - 13 3/8 x 16 7/8 in, 340 x 430 mm
Ecu - 15 3/4 x 19 5/8 in, 400 x 500 mm
Grand Aigle - 27 1/2 x 41 in, 700 x 1040 mm
Jesus* - 22 x 28 3/4 in, 560 x 720 mm
Pot - 12 5/8 x 15 3/4 in, 320 x 400
Raisin* - 19 5/8 x 25 1/4 in, 500 x 640 mm
Soleil - 22 7/8 x 31 1/2 in, 580 x 800 mm
Telliere - 13 3/8 x 17 1/4 in, 340 x 440 mm
Those marked with an asterix (*) were possibly the most widely used until metrication.
GERMAN TRADITIONAL PAPER SIZES
Bienenkorb - 14 1/8 x 17 3/4 in, 360 x 450 mm
Bischof - 15 x 18 7/8 in, 380 x 480 mm
Kanzlei - 13 x 16 1/2 in, 330 x 420 mm
Lexicon - 19 5/8 x 25 5/8 in, 500 x 650 mm
Pro Patria - 13 3/8 x 16 7/8 in, 340 x 430 mm
Register - 16 1/2 x 20 7/8 in, 420 x 530 mm
These sizes were standardized in 1884
TRADITIONAL DUTCH PAPER SIZES
Olifants - 24 3/8 x 28 3/8 in, 620 x 720 mm
Royaal - 20 1/2 x 24 3/8 in, 520 x 620 mm
Schrijfformat - 13 3/8 x 16 1/2 in, 340 x 420 mm
Vierkant - 16 1/8 x 24 3/4 in, 410 x 620 mm
Sizes in use around 1800