It is a type of material that stretches and is used especially for making clothes fit tightly.
Lemon & Soda LEM3985C - Shirt Poplin LS for her
FLEXFIT FL7706RS - Recycled poly twill cap
Yoko YHVW064 - Reflective strip
Gildan GI18000B - HEAVY BLEND YOUTH CREWNECK SWEATSHIRT
Gildan GI18500B - Heavy Blend Youth Hooded Sweatshirt
Gildan GI18000 - Heavy Blend Adult Crewneck Sweatshirt
Gildan GI18600 - Heavy Blend Adult Full Zip Hooded Sweatshirt
Gildan GI12000 - Dryblend Adult Crewneck Sweatshirt