How to use thinning scissors (with video)
Using thinners requires correct technique. The wrong technique can cause the notched teeth to hit or catch. If you find the teeth of brand new thinners, blenders or chunkers seem to hit or catch as you cut, stop and check your technique before you accidentally damage the teeth. Thinners are less forgiving of incorrect technique than solid-blade scissors. Don't keep using a thinner if the teeth are catching or hitting. Check your technique first before continuing.
This usually happens due to applying pressure incorrectly (to one side or the other), often with your thumb, causing the teeth to touch. This video below shows you correct technique and what to avoid so the teeth don't catch. You'll find more on YouTube also if you search how to hold dog grooming scissors