A good flight starts at the printer.
Choose your sheet, check the scale, and print just one side.
Choose your paper
Use US Letter or computer paper (8.5 × 11 inches), or A4 (210 × 297 mm). Computer paper comes in different sizes: check the packet and choose the matching file. Start with ordinary uncoated printer paper.
Print one side only
The two-page PDF contains a fold sheet and a separate optional guide. Print page 1 single-sided. Keep page 2 on-screen, or print it on a separate sheet. Never print it on the back of the fold sheet.
Use actual size
Choose 100% or Actual size, portrait orientation, and the correct paper size. Turn off Fit to page. Measure the 25 mm scale mark with a ruler before folding. Normal printer margins may hide the ends of dotted lines; use the guide to extend those folds to the paper edges.
Begin at number 1
Place the sheet printed side up with a short edge at the top. Match each number to its guide step. A number may cover two matching folds. Go slowly; a hidden number does not mean you need to print the back.