ways to make small-ish modifications to recloseable plastic bags

It's possible to reduce both the width and/or height of a reclosable bag.

• the "hot knife" method [1]
• the "coat hanger" method [1]
• the "crimp bag between two pieces of metal and heat the bit of plastic that sticks out" method [1]

It's possible to create split compartments inside a ziploc bag.

• Examples, so this concept doesn't get lost:   [1] [2] [3]