Gage is not necessary as it is a bag, Any DK yarn will work but cotton is recommended for stiff structure.

Crocheted with a medium tension I used all three hanks with about 1-2 yards left.

Size can be adjusted by the number of beginning chains, as long as its an even number.

My Gauge is loose with a H8/5.00mm hook, so if you are a tighter crocheter you can adjust gauge by using a larger hook (one size up should do it)

This pattern can be done in Sc and Dc. The Dc version would result in more starting stitches and be a throw.