Here are some simple tips on how you can use a regular piece of 8.5” x 11” paper to visualize how large your prints will be.
If you want a nice, big graphic, 11 to 13 inches is typically the size of what you’ll print on the shirt, depending on the size of your shirt. The longest side of a sheet of paper is 11 inches long, giving you a nice visual representation of how large your graphic may look on a shirt.
Typically, a good size for a chest print is between 3 and 4 inches wide. If you the wide end of the sheet of paper in half again, you get a 4.25” space, giving you a good visualization of how large your 4” graphic can look. If you fold it in by around an inch, you can compare the 4” with the 3” size to see which works best for you.
One other way that screen printers approximate measurements is by using their hands. Placing three fingers down on a shirt is around the size of a sleeve print, or two inches wide. Placing four fingers down will give you a width of around 3 inches and five fingers will be around 4 inches, giving you the rough size of a chest print.