Tools, Tips, Technique
Extension clips (combs) are usually found in hair specialty stores. There are 3 sizes that are most commonly used - small, medium, large, and 3 colors, white, light brown and darker brown.
They are fairly cheap and can be bought for anywhere between around 50 cents to $ 1. They usually cost less if bought in bulk.
Extension clip combs need to be attached by sewing them to the thin line of tape that holds the hair extension together.
When sewing the extension combs use a needle and thread. I recommend leaving the thread a little loose so there is some give and they can move more freely and naturally when attached to the models hair.
For an extension with a width of 8cm -12 cm, two medium combs are more than enough to secure the extension. If in doubt you can place a third much smaller one between the two regular sized combs you have used.