Hello MITRA,
I’ve been playing with egg tempera as a ground for metalpoint. If layered thinnly and allowed to cure egg tempera is, like casein, a good ground (due to its PVC); yet I rarely see tempera mentioned as a metalpoint ground. Any thoughts?
Also, is egg tempera as vulnerble to hydrolysis as oil paints?
Thanks,
Koo Schadler
Egg tempera does seem a bit softer; even on a thinnly applied (2 layers), fairly well cured (sevral weeks) ET surface a fine metal nib, too assertively applied, appears more apt to scratch off a fine dusting of ET (versus a glue or casein based one). But a very minimal amount of ground was affected, it wasn’t problematic. The metalpoint marks themselves were fine and rich, and an added benefit is the sulphur in egg yolk speeds up tarnishing. So I think ET makes a good metalpoint ground, tho’ I need a lot more direct experience to understand the pros and cons for sure – I’ll let you know. Koo
Hi Koo
Neither oil paint nor egg tempera are overly sensitive to hydrolysis in normal conditions (no contact with acids/bases, etc) Lean tempera would likely make a fine metalpoint ground although it does seem, at least initially, to be less hard than one bound in animal glue. On the other hand, it is far less responsive to changes in relative humidity than animal glue. Let us know about any tests that you perform.