The sleeveless design of a muscle T-shirt is designed to show off the wearer's strong physique and sculpted biceps. Because muscle T-shirts have become a fashion statement for guys of all shapes and sizes, stores stock them in all colors and styles. But instead of shelling out money for a new one, grab a T-shirt you already own and convert it into a muscle tee yourself.
Choose your shirt wisely. Muscle tees are meant to have a slim fit, so pick one that just skims the body and isn't too tight or too loose.
Press your T-shirt with an iron. Fill the iron with water so that it steams and turn it to the hottest setting. Lightly press the shirt until any wrinkles are gone. It doesn't have to look perfect, but it needs to be smooth so that cutting will be easier.
Remove one sleeve at a time. Using a pair of sharp scissors, follow around the armhole and snip just inside the armhole seam. Cut slowly and carefully, as closely to the seam as possible. Repeat with second sleeve.
Turn the shirt inside out and lay it on a flat surface.
Turn 1/2 inch of the cut edge of the armhole to the inside of the shirt. Hold the hem in place with straight pins placed about 1 inch apart around the armhole.
Press the armhole seam with an iron to create a nice, flat edge.
Set your sewing machine to a stretch stitch and sew around one armhole 1/4 inch from the edge. Remove pins as you approach them. Repeat with the other armhole.