Professionals demand the thinner and more precise convex edge shear which delivers a cleaner, sharper cut and aids in slide cutting.
Many unskilled sharpeners will change a convex edge to a blunt beveled edge – “chopping” excessive metal off the blade and removing years of life from your shears.
Restoring a convex edge can often be done!
This is a lengthy process requiring advanced skills. This could be related to the skill and effort needed by experienced stylists who have to perform corrective coloring, when you have to go back to a base color and start over again. There is an additional charge for restoring badly sharpened shears.