Support common paper formats / Save custom formats

Hello, first off, let me tell you: I really like your application! You did something great.

Now, onto my feature idea:

When creating a map, I can choose a format/aspect ratio. Since I print my maps quite often, I’ve noticed that some of them get cropped at the edges when using the given aspect ratios. I would love it if you could support the common paper sizes used around the world. I believe in the USA, these are:

Letter (8.5 × 11 inches)Legal (8.5 × 14 inches)Tabloid (11 × 17 inches)

For most other countries, the standard DIN sizes are:

A3 (11-3/4 × 16-1/2 in | 297 × 420 mm)A4 (8-1/4 × 11-3/4 in | 210 × 297 mm)A5 (5-7/8 × 8-1/4 in | 148 × 210 mm)

If supporting all these formats isn't feasible, or if there are many more standard sizes than I listed here, how about allowing users to save custom aspect ratios as presets? That way, I could set my preferred format once and simply select it whenever I create a new map.