Elastic usually comes in two colors, black and white. There are two ways elastic looks. The best type for clothes is the “no-roll” elastic. It doesn’t roll or twist, so it is more comfortable. I also is stiffer, so it is easier to thread though the casing. The rolling elastic (the one that isn’t no roll) is the best for tings like scrunchies because it is easier to stretch and twist an you want to twist it around your hair. Lingerie elastic is best for underwear and swimsuits.
Be sure to use dark elastic with dark color fabrics and light colored elastic with light colored fabric.
There are many sizes od elastic from narrow to wide. Narrow is great for wrist bands on clothes and also on doll clothes. Wider elastics are used where there are wider casings. You want to make sure that your elastic is only about 1/4 to 3/8 of an inch less than the width of your casing (1/2 inch at the most). You can use a narrower elastic in a scrunchie
Try a nice stretchy elastic in last week’s pattern for a head band and make a scrunchie.