Place the cardboard (or plastic sheet) inside the shirt to prevent the paint from staining the back of the shirt.
Position and stick the first piece of tape just below the armhole. Then position the other pieces of tape below, leaving enough space in between to paint half the width of the tape. Continue until there is 6-8 cm left at the bottom of the shirt.
Using a flat paint brush, paint the Setacolor colour between the strips of tape, in a uniform manner, until flush with the seams on the side of the shirt.
Allow to dry at least two hours before removing the tape.
Then iron the shirt inside out for 5 minutes to set the colours. The shirt will now be resistant to washing at 104°F