I know this is probably a too vague question… From what I’ve studied so far, it seems that ACM panels are an almost perfect surface to paint on (after being properly prepared for that).
Then a friend questioned my belief and told me that copper was actually superior to ACM panels, at least for oil painting. I have some doubts yet I couldn’t fail to notice that the paintings on copper that I’ve seen are much better preserved than the ones on other traditional supports.
What is the very best support for oil paints currently available?
Thank you!
If the question is about which support best ensures durable results, that’s a lot easier and less subjective- aluminum honeycomb panels are excellent in that respect. I recall Mr. Gottsegen said he had determined through testing that aluminum provided a terrific pairing with acrylic dispersion primer provided the panel was finely grained with steel wool and washed with denatured alcohol before priming.
That said, “best” is not going to mean the same thing for all artists. Some artists favor support materials that have known drawbacks. This might be for practical reasons like availability, affordability, the ability to cut panels in-studio, or whether glue joinery and hardware can be easily incorporated. I expect some artists will favor MDO plywood, for example. Others may argue that stretched linen is best for their work, regardless of challenges that emerge as the picture approaches antique age.
If one looks at the existing examples of 17th century oil-on-copper paintings that you see in museums, it does appear that it is the superlative surface. Some are so pristine as to look like they were painted this year. This is somewhat misleading. Oil-on-copper paintings tend to be in one of two states of condition, really good, or abominably bad. This dichotomy really has to do with the history of storage conditions. Copper is very reactive. If the painting was stored in a higher humidity environment, it is likely in terrible condition, if in low humidity, possibly great condition.
This indicates that while copper can be used for permanent paintings, it is not ideal. Copper as a substrate was discussed in this thread:
https://www.artcons.udel.edu/mitra/forums/question?QID=345
As Sarah pointed out some of the problems with copper as a substrate are discussed here:
https://www.academia.edu/1031822/The_degradation_of_oil_painted_copper_surfaces
and
http://www.lalibreria.upv.es/portalEd/UpvGEStore/products/p_2102-3-1
I will not go into what is the perfect surface because that is both subjective and I am not sure that we have tested some of the candidates well enough yet to call one of the contestants a definitive winner.