Just Allan said:
Well the "A"s just double/halve. Use A4 as the centre point, since
everyone knows what A4 is, and:
A2 = two A3's
A3 = two A4's
A4
A5 = half an A4
A6 = half an A5 (quarter of A4)
Halving at each step is quite common for all paper series and results,
obviously, from the need for efficiency and minimum wastage in the paper
industry. The B series do the same, but there are two variants of the B
series - ISO and Japanese (JIS). These are both metric sized sheets,
but there are lots of paper standards, and the sizes that Stewart is
seeing in stores are Imperial sizes.
ISO-A series is based on A0 which has an area of 1 square metre.
ISO-B series is based on B0 which has a short side of 1 metre
JIS-B series paper is based on B0 which has an area of 1.5 square
metres.
Thus the ISO-B0 sheet has an area of the square root of 2 in square
metres. There is also an ISO-C series, which is mainly used for
envelopes, but which is based on C0 having an area of the fourth root of
2 in square metres.
For both series the sides are in the ratio of 1:square root of 2, which
is roughly 1:1.414, so that each time the sheet is halved, each half has
the same aspect ratio as the original. This means that an image that is
cropped to fit one size of these series will, with suitable
magnification, fit all sizes in all series without cropping or borders.
Size ISO-A ISO-B JIS-B ISO-C
0 1189x841mm 1414x1000mm 1456x1030mm 1297x917mm
1 841x594mm 1000x707mm 1030x728mm 917x648mm
2 594x420mm 707x500mm 728x515mm 648x458mm
3 420x297mm 500x354mm 515x364mm 458x324mm
4 297x210mm 354x250mm 364x257mm 324x229mm
5 210x148mm 250x177mm 257x182mm 229x162mm
6 148x105mm 177x125mm 182x128mm 162x115mm
7 105x74mm 125x89mm 128x91mm 115x81mm
etc.
Imperial paper sizes include the US Letter and Legal series, similar to
the metric standard, in that sequential steps are double the previous
size, but in inches.
Size Letter Legal
US A 8.5x11in 8.5x14in
US B 11x17in 14x17in
US C 17x22in 17x28in
US D 22x34in 28x34in
etc.
Note that, since the original does not have a 1:1.414 aspect ratio, the
aspect ratio of the US paper series is inconsistent when halving or
doubling sheets, but changes between a ratio of 1:1.29 and 1:1.55 for
letter and 1:1.214 and 1:1.647 for legal at each step. This means that
an image that fits perfectly on US B will have to be cropped or leave a
border on two sides when printed on US A, whether in the letter or legal
sizes.
The first known record of paper size standardisation is a marble plaque
in Bologna, Italy announcing a statute of 1398 and showing paper sizes
very similar to the modern ISO-A series - even though the metre was not
formally defined for another four centuries. There are hosts of other
paper sizes as well and numerous references, but the most useful source
of paper sizes should be the listing in the dialog box of your printer.
;-)
