Plique-a-jour is a French term used in jewelry making to describe a technique of enameling where the enamel is translucent and there's no backing. If you're trying to describe this technique but can't think of the exact word, here are some synonyms to consider:
1. "Openwork enameling"
2. "Translucent enameling"
3. "Unbacked enameling"
4. "Stained glass-style enameling"
5. "Windowpane enameling"
6. "Light-catching enameling"
7. "Lacy enameling"
8. "Frosted glass-style enameling"
9. "Thin-layered enameling"
10. "Delicate enameling"
Whatever word you choose, just make sure it accurately depicts the unique process of plique-a-jour enameling.