Hi.
This is my interpretation.
An infill is simply filling in the gap at the cuticle and nothing more.
A backfill is moving the white smile line back as it grows out and nothing more.
I prefer to use the term rebalance because I never simply put more product on, like most techs I shorten the nails, move the apex back, general tidy and then apply new product, thereby totally rebalancing the shape of the nails.
I use the term French rebalance for when I move the white smile line back as it grows out as well as doing all the aforementioned to the nails.
That is my understanding of the terminology and what I use.
But clients still call it an infill as if you just stuff a bit of product in there and that's it.:irked: You try to educate them but they sometimes don't care what it's called as long as their nails look great