When it comes to choosing [[s1|card and paper supplies]] for your scrapbooking and card making projects, it can be difficult knowing where to start. With so many different sizes of card and paper available, we thought we'd try and help by giving you a quick reference guide. ==Paper/Card Sizes Paper sizes can be pretty confusing. Though the 'A' system is organised in a logical way (A1 is bigger than A2, A2 is bigger than A3, etc), it can be tricky to remember which size is smaller than which. Just remember - **the bigger the number, the smaller the paper.** Let's look at the dimensions of the most popular sizes: |:=Size|Size in mm (h x w)|Size in Inches (h x w)| |A1|841 x 594 mm|33.1" x 23.4"| |A2|594 x 420 mm|23.4" x 16.5"| |A3|420 x 297 mm|16.5" x 11.7"| |A4|297 x 210 mm|11.7" x 8.3"| |A5|210 x 148 mm|8.3" x 5.8"| |A6|148 x 105 mm|5.8" x 4.1"| |A7|105 x 74 mm|4.1" x 2.9"| Starting from A1 (the biggest), the sizes go down as if you have folded the previous sheet of paper in half. ==Card Blank Sizes When it comes to [[s2|card blanks]], the size given refers to its folded size - ie the front face of the card. So for example, an A5 card blank is a card with an A5 front, even though the sheet of card used to make it is A4. Square card blanks have simple measurements in cm or inches, and tall DL card blanks are in a category all their own - they are the same size as a sheet of A4 folded to a third of its size, like a business letter. The measurements of a DL card blank are 21 x 9.9 cm (8.3 x 3.7 in). ==Envelope Sizes Generally speaking, envelope sizes are given as C plus a number, and this number corresponds to the paper or card blank size that fits inside the envelope. For example, C4 envelopes will fit an A4 card blank or unfolded sheet of A4 inside. The measurements are slightly bigger for the envelope - ie a C4 envelope will be a bit larger than A4, to allow plenty of room. There are also square envelopes to fit square card blanks, and DL envelopes to fit tall DL card blanks. Again these will be slightly larger than the card blanks they are designed to hold.