A4
210 × 297 mm · ISO 216
By sheet
Pick the paper your printer (or plotter) actually owns
Every grid in the library is rendered against both the ISO A-series and the ANSI/US loose family, so you can print a 1:50 plan on A3 in Berlin or 11×17 in Brooklyn and trust that the proportions survive.
A3
297 × 420 mm · ISO 216
A2
420 × 594 mm · ISO 216
Letter
216 × 279 mm · ANSI A
Legal
216 × 356 mm · US Loose
Tabloid
279 × 432 mm · ANSI B
The two systems, side by side
The international ISO 216 paper system - A4, A3, A2 and so on - is built around the elegant property that each successive size doubles the area of the last while keeping the same aspect ratio of √2:1. That's why an A3 sheet folds neatly into two A4s, and why architectural plan series scale predictably.
The North American loose family - Letter (8.5×11"), Legal (8.5×14") and Tabloid (11×17") - predates ISO 216 by decades and remains the everyday office stock in the United States and Canada. GridCraft renders every grid in both families so you don't have to choose.