Pour a layer of emulsion into the spreader approximately 1/2 inch thick, then shake the spreader so it is evenly dispersed.
Lean a screen at an angle, then place the spreader at the bottom of the screen and swipe up to the top.
Lean the screen off the wall so extra emulsion falls back into the spreader, then place the screen in a dark enclosure, like a closet or cabinet, resting it flat.
Repeat for the remaining screens, or for as many screens as you can fit at one time.
Print off each number from 0 to 9 in the size and font you want on your jerseys onto its own clear sheet.
Remove a screen from the dark location after 45 minutes.
Place the 0 sheet on the light box, then place the screen over the sheet.
Place a piece of plywood larger than the number but smaller than the screen so that it fits inside the frame, atop the screen to hold it flush against the sheet, then place heavy objects on top of the board to hold it down tight.
Turn on the box for 4 minutes, being sure not to look directly at the UV light bulbs, as they can damage your eyes if stared at.
Remove the weights and board, then bring the screen to a hose or the shower and rinse off the screen. The emulsion behind the number on the screen will rinse off.
Repeat for the remaining numbers.
Place the cardboard sheet inside the shirt you will be screening, then place the screen for the first number for the jersey over the shirt where you want the digit located. For a single digit number, center the number. For a double digit number, offset the number so the number will be centered after the second digit is applied.
Apply silk screen paint to the screen over the emulsion at the bottom of the number, then spread the paint out using a squeegee.
Remove the screen and set the shirt aside to dry while laying flat.
Repeat for each jersey being screened.
Add a second digit to any double digit jersey after the first application has dried.