MITRA Forum Question Details

​Hello Lora,

Perhaps the lack of response indicates that you are breaking new ground here - so please continue your experiments and let us know how they work out.

For the record, the idea that egg tempera is capable of a soft "egg shell shine" (a term I've used myself) but no more, isn't accurate.  I've seen well-tempered egg temperas carefully, gradually buffed up to a lacquer-like high gloss.  My presumption is that this comes from gradually smothing out the irreuglar surface created by the high pigment load in egg tempera; a gentle, careful polish softens the rough edges of particles proturding above the paint film, to create a more mirror-like surface.   If an attentive polisher avoids visibly marring the surface as he or she polishes, I don't know if there are other risks to pulling out a strong shine (such as weakening the paint film).  Do conservators have any thoughts or experience with this?

Koo Schadler

​Hello Koo and Brian,

Thank you so much for your responses!

First to Koo, I think we may have stumbled on "Egg Tempera Misconception" #31 in your list? In #28 you mention the "egg shell" shine but in your response to my question you mention that it is possible to achieve a "mirror-like" finish. That would indeed be another misconception as the most common characteristics mentioned about ET (in addition to the "high key") is the "matt finish." So it is exciting to me that I may be able to pull out a lot more shine. I am in the non-varnish camp because I do not want the saturated look of my ET paintings but I would like more gloss.

Brian your caution about power polishers is well-taken and I promise to try out any power tools on sample or reject ET paintings. The reason I am looking into a "Dual Action" orbital buffer is, "The rotating and orbiting of the pad produces what many refer to as a "jiggling" motion. This irregular motion prevents the polisher from burning the paint, which refers to removal of paint below the clear coat surface. Dual action polishers are very USER FRIENDLY because they produce very little heat compared to a rotary polisher. 

That said, as you say, they are meant for automotive finishes. I am looking into the type of pads available and most are "foam." There are some that do cut into the surface and others that are for polishing only. There are others that are "microfiber. " The finishing microfiber pads which are supposed to be safer but I need to look into it more. I have not yet sprung for the machine but did order a "finishing" microfiber pad that I thought I would try out without the machine first.

Which brings me to the question: is there any concensus on the best cloth for polishing an ET? I've heard silk, flannel or T-shirt material. Has microifiber been tried for hand polishing?

Again thank you both for your sage advice!

Lora

​Hi Lora,

There's a balance in a polishing cloth between smooth and abrasive - you want enough abrasion to buff the surface, but not so much that a painting is scratched or pigment lifted. I've always found a fine weave cheesecloth to work well; however I've seen many newcomers polish either inattentively or over enthusiastically, and consequently mar the surface, so I also recommend well worn cotton or a piece of silk - both are less abrasive materials and thus safe options for beginners.

Your idea of using a microfiber is great; I just tried it and fine cheesecloth, side by side on the same painting, and the microfiber gave excellent results (more shine than the cheesecloth).  I would just say that for any newcomers to polishing (which of course you are not) practice with a less abrasive fabric to start or, if using microfiber, do so with attention and care.

Please let us know about your Orbital buffer experiments.

Koo

​I forgot to say, Lora - yes, another one for my list of Egg Tempera Misconceptions.  I've already added it, up to 32.  Thanks!  Koo

​Thank you Koo for your run down on polishing cloths. I recently used some white cotton photographer's gloves and really enjoyed "caressing" my painting double handed without any bunched up cloth. 

I still haven't sprung for the Dual Action Orbital Buffer. Some brands have a "slow start" capability that seems like a wise feature but adds to the cost. Will keep MITRA posted. Thanks, Lora