Upload new images. The image library for this site will open in a new window.
Upload new documents. The document library for this site will open in a new window.
Show web part zones on the page. Web parts can be added to display dynamic content such as calendars or photo galleries.
Choose between different arrangements of page sections. Page layouts can be changed even after content has been added.
Open the Navigation Management window, which can be used to view the full current branch of the menu tree, and edit it.
Move this whole section down, swapping places with the section below it.
Check for and fix problems in the body text. Text pasted in from other sources may contain malformed HTML which the code cleaner will remove.
Accordion feature turned off, click to turn on.
Accordion featurd turned on, click to turn off.
Change the way the image is cropped for this page layout.
Cycle through size options for this image or video.
Align the media panel to the right/left in this section.
Open the image pane in this body section. Click in the image pane to select an image from the image library.
Open the video pane in this body section. Click in the video pane to embed a video. Click ? for step-by-step instructions.
Remove the image from the media panel. This does not delete the image from the library.
Remove the video from the media panel.
Hi, I'd really appreciate some advice on an unusual query; I've been referred to this amazing website through the Painting Best Practices Group on Facebook. I've had a good look through the resources and forum threads on here, but I still have some questions:
asked by a jewellery designer if I could paint miniatures in oil
paint onto slightly concave 22ct gold ovals, circa 1mm thick, to be
set into a bracelet. I’m wondering what a concave surface will do
to the paint layers over time.
painted on convex gold domes for the same client, treating it like
painting on copper/on top of gold leaf (there was limited testing I
could do on solid 22ct gold!): the gold was completely obscured, as
it was purely to make sure the whole jewellery piece was made of
precious materials. I very lightly abraded the gold, degreased it
with denatured alcohol, then two thin coats of a flexible primer:
Liquitex clear gesso primer (chosen because it was difficult to
scrape off copper that had been prepared in the same way. It was also
quite difficult to remove from the gold dome two months down the
line, i.e didn't peel, when I removed the finished painting to make way for a new
design). I then painted in very thin layers using the minimum amount
of medium: progressively fatter turps and linseed oil. The final
paint thickness is very thin. 6 months on, the convex domes appear
unchanged (if 6 months is a reasonable cure time? I’m expecting the
cure time to be slow because of the circa 1mm thick metal support,
but it is very thinly painted).
For the concave
domes, I’d be using the same process and medium.
- Is a concave
surface inherently unsafe for indirect oil painting?
- If not, would an alkyd primer, or a
lead-based primer be a better product than the acrylic gesso primer? I'm working on the assumption that the gold is largely chemically inert, with circa 2% copper and circa 6% silver - I gather
lead primers bind chemically to copper, but my only option (as I'm in the UK and lead products have been phased out) is an old tube of Daler Georgian Flake White – it doesn’t say
if it contains zinc, or if it’s linseed oil. I don’t know if this
would be up to snuff as a priming layer at all.
Thank you for
reading this long-winded post!
Move this whole section up, swapping places with the section above it.
I really do not think that concavity of convexity of the
rigid substrate would add any additional complications other than it is harder
to paint on such a surface.
It seems to me that your procedure is sound. I see no
benefit of using an oil ground on a metal surface in this instance, since this
is really just a first application of oil paint, not really different than
subsequent applications of oil paint. If
you needed an opaque ground layer because your later oil paint layers would be
transparent, that is a different situation. If your acrylic dispersion layer
adheres well, it is likely a fine system. However, there are resins that are
more sympathetic for most metals. The acrylic B48N resin is often used in
conservation to coat metals as it has particular affinities for metals. Since
the metal in this case is inert, this may be unnecessary. It is insoluble in
mineral spirits so it could be used if that is your oil paint diluent. As to
alkyd primers, you would really need to do a test to see if they are superior. They
would provide the benefit of being insoluble in most organic solvents after
This brings me to the subject of varnishes. Are these
varnished? Is it possible that the varnished would need to be removed at some
point? If the answer is no to both questions then the answer is easier, just
pick what works best. If the answer is yes, one needs to be thoughtful of the
solubility of the gold mordant (is the gold adhered with a dispersion or oil
mordant, and what are the solubility issues) and the solubility of the initial “size”
or “ground” layer.
You mention flexibility of the “size” or “ground” layer. Why
is that quality needed here? Is the substrate likely to be stressed or deformed
when insetting into the bracelet? Perhaps that could be an issue and if so, you
would ant to adhere them before the paint becomes overly brittle. Likely this
in not a problem.
You are correct in stating that the scuffed predominantly
gold surface is unlikely to tarnish or corrode and should be quite stable in
terms of chemical reactivity.
6 months seems like a reasonable cure time. Personally, if
you are painting the oil paint thinly and in very few layersand on a relatively slick surface, you want to make
sure of adhesion in this situation and not worry as much about issues relating
to complex layering. If it were me, I would probably progressively add small
and judicious amounts of a quality alkyd medium to provide a bit more adhesion.
Thank you so much
for your thorough and speedy answer, Brian! It’s lovely to have
your sound advice – it’s been a very long research process trying
to muddle my way through! I will research the cues you gave me.
Re. the choice of a
flexible priming layer (the acrylic dispersion), it was just me being
worried that the priming layer might contract and be stretched over
the dome as it cured, so I was worried about cracking down the line. There isn’t much stress to the painting in fitting it into
the jewellery as the support is thick enough to be rigid, and it’s
not a push fit/solder but a screw fit.
Re. varnishing, the
support is solid 22kt gold, circa 1mm thick, so there’s no mordant
to worry about happily! The only reason the support is solid gold and
not an insert is to keep the whole jewellery piece made of precious
materials – it’s completely obscured by the painting, although
the gold is visible from the back of the piece.
Yes, all the pieces
are/will be varnished - it’s a tad convoluted however: the first
set of paintings, without glass, were varnished with Gamvar when hard
dry (I used a dental tool instead of a thumb given the scale!) as
speed was important. Then the pandemic hit and the launch was set
back anyway – so I now have the opportunity to put a more durable
varnish on those pieces, given that they are 6 months cured, removing
the Gamvar first. My current thinking after researching it best I can
is that a high molecular weight polymeric varnish like Golden MSA or
Conservar Polymeric Varnish would provide a more durable, and
thicker, layer – I may then have to add a layer of Gamvar on top to
try and restore its previous appearance…
The client is
considering putting Sapphire glass over future pieces as a protective
measure; in this case, I would still varnish them to saturate the
appearance, using Gamvar as it’s not exposed to
wear and tear and is purely an aesthetic decision.
Whether the sapphire glass
would cause problems is another research question for me – I’d really appreciate your
advice if you have time! Currently, I’ve got as far as this: it
would be safe to add glass over the painting, spaced away from it,
once hard dry and post Gamvar, as the oxygen in the paint film is
sufficient to keep the curing process going, bouncing in and out of
the paint film and being recycled. The dome wouldn’t be soldered in
place, only a tight screw fit, so as far as creating a microclimate
between the glass and the gold is concerned, I don’t know if
there’d be any issues with trapping moisture – as there wouldn’t
be any water in the paint film or support, and presumably as there’s
no air gap no moisture can get in? I can’t find any examples of a
sealed, non-porous support, non-aqueous medium painting – although
I’m sure miniature portraits on copper have been placed in lockets
Apologies for another long and rambling query! Thanks again for your time.
I see that I did not return to answer your additional
question. I would think that the glass would be fine as long as the paint has dried
long enough to be varnished. You would not want the varnish (or paint) to touch
the glass but it does not appear that this would occur in the scenario you laid
Thank you, Brian! That's great to hear. (no worries, I assumed I'd just been cheeky in expecting answers to such long and convoluted questions!)
Best wishes, Ellie