You will need the following materials to make the backpack:
Two colours of worsted weight yarn. 275 yards for the bag and approximately 75 yards for the cap.
5.5mm crochet hook
measuring tape
scissors
stitch markers

The backpack liner is optional. The materials you will need for that are:
Piece of fabric measuring 18”x21”. You can find precut fabric at Michaels, Walmart, etc.

Skill lever for this project is intermediate.