Here's the answers to some of those questions you might have
What are the different paper sizes
Most people are aware of A4 paper. It is a standard size around the world, at 210mm x 297mm. Then there are other sizes like A5 and A4. Here's how they work. Fold an A4 sheet in half. That's A5. Fold it in half again, and you have A6 and so on. Same goes for A3. If you double the size of A4, you get A3. Double that and you get A2.
What about SRA and B sizes?
SRA (supplementary raw format A) is an enlargement of the A series paper sizes. Used mainly for commercial printing, as it allows for grip, printing bleed and trimming. The B series paper sizes were created in order to provide paper sizes that weren't covered by the A series, but also use an aspect ratio of 1:root2.
So how big are they?
What about C sizes?
C Series is the relative envelope to paper size. If you want to send an A4 letter, without folding it, you need a C4 envelope. Fold it in quarters, and pop it in a C6 envelope. Fold it in thirds, and a DLE is the envelope for you. For more information, check out our Envelope Information page.
If I want it cut down, how many do I get out per sheet?
This can vary, depending on the size of the master sheet and the size you want. Then you have to consider if grain direction matters. (Not sure which you need, check out grain direction below).