B-grade molds are new, never used. B-grade molds have small imperfections and most will be covered up with a layer of clear coat.
The imperfections can include any of the following:
-cosmetic imperfection (dust and specks inside the mold)
-smudge on mold surface
Mold details: https://ellafulmolds.etsy.com/listing/978560267/christmas-ornament-photo-frames-silicone