No tool has done as much damage to hair as the thinning shear/scissor. Back in the 1960s we called it the “Saturday Shear”. Saturday was a very busy haircutting day in that decade and those “thinners” would help give fast haircuts. Precision haircutting it was not! You would run the clipper up the sides and grab the thinners to “chomp” away at the heaviness left on the upper sides. Some more chomping on the top followed by some greasy hairdressing to hold down those wrecked hairs. It was a terrible way to cut hair that needed lots of grease to look decent (?) at all.
With the shears that have little teeth, some hairs get cut shorter, some get a partial or nicked cutting instead of being completely cut and some hairs are left uncut. The shorter hairs push out the longer hairs, both the nicked ones and the longer uncut hairs. The hair is left puffy and those partially cut hairs have a hard time laying in with their neighbors. If no hairdressing or gel is used after the chomping is done, you have damaged hair that looks a lot like stomped-on straw.
My videos do not show thinning shears being used, however I do own a pair and I use them rarely. Here are a few instances:
1. It is common for people to say “thin out the top”. At least nine times out of ten that is their way of telling to cut the top shorter to get rid of the long heavy hair that is prone to messiness. Once in a while a person really wants the use of thinners. After explaining a better approach to “thinning out the hair” is to cut the hair as short as possible so it still lays well, they may still insist on the use of thinners. Then the customer gets what they want, but I use them sparingly out towards the ends of the hair–I do not thin the hair close to the scalp.
2. Once in a while I have a client with a crown area cowlick that needs extra length to lay down. To blend that longer hair with the shorter hair toward the bottom of the back, I will do a little thinning.
3. Some folks with extra curly hair want their hair thinned even after it has been given a short cutting that minimizes the curls. Thinning the ends can relax the curls somewhat, so it is easier for the curls to lay into waves.
If you love what you do, you will never work a day in your life.