What part of sign language don't you understand? T shirt Solid colors: 100% Cotton; Heather Grey: 90% Cotton, 10% Polyester; All Other Heathers: 50% Cotton, 50% Polyester Imported Machine wash cold with like colors, dry low heat Deaf culture, finger spelling, hand talking, american sign language interpreter, non verbal t shirts - GREAT gift idea for ASL, deaf - HoH hard of hearing teachers and students T-shirts are a fun, inexpensive gift idea for Birthdays, Christmas, Halloween, Thanksgiving, Valentine's Day, Anniversary, Graduation, Mother's Day, Father's Day, Grandparent's Day, or any special occasion. Lightweight, Classic fit, Double-needle sleeve and bottom hem