Am wondering if any the artists and jewelers here, that use etching, have any thoughts on applying a repeatable photo/printer resist to a compound curved surface…i.e. approximately the surface of a soup bowl? Repeatable in some manner vs. hand drawn. Puckering/wrinkling the substrate is the main issue that can’t seem to be overcome. Input most appreciated.
Just a thought, but perhaps a transfer printing process as is used in ceramic transferware might work. Lots of experimenting would be needed to find a resist that could be printed and then transfer cleanly to the piece from the paper carrier.
Ahhh haaaaa I knew
there would be a new line of creative thought on here. I’ll
start some research on that topic immediately. Not only is the
search on for a technique, but also a resist that can hold up
to acid. Thank you. Any other
research topics would
be very welcome.
What if you stretched a nylon stocking (or Spandex, or any stretchy fabric with an open mesh structure) over an embroidery hoop, then applied latex (or a synthetic rubber such as silicone or urethane) to form the resist pattern. This could be painted on directly, or screened on with a conventional silk screen. Once the rubber was set, you could stretch the nylon-filled hoop over the bowl shape and apply asphaltum (or another acid-proof resist agent) through the nylon with a squeegee.
AW So…in
essence silk screening using a flexible rim to conform to the
surface??? Did I get that right? Maybe not necessarily a
flexible rim but a rigid rim large enough in size that the
screen could be pushed onto the surface to drape the surface
tightly enough to squeegee a resist? Not familiar with how
much detail a fine screen can hold.
I use PnP blue- an iron-in resist. C-7 PnP Blue Transfer Film – Thompson Enamel It would definitely work on the outside of a bowl, but the inside would be tough…
When I was a ceramicist, I used these flexible silkscreen sheets to apply glaze patterns. You can expose them with just sunlight. https://ezscreenprint.com/ You can cut them small and apply them anywhere since you don’t need a frame. However, I can’t think of a resist for etching that you could silkscreen.
I was thinking of a rigid rim that was larger than the soup bowl, which would, as you say, allow the screen to conform tightly to the outside surface while you screened on the resist. (The inside, as noted, would be a lot more difficult). Asphaltum has traditionally been used as an acid resist, and I don’t see why it wouldn’t work in this application. Silk screens can transmit fairly fine detail; the critical factor would be the method used to create the mask. Here’s a picture of an embroidery hoop, in case you’re not familiar with them: https://www.google.com/shopping/product/9980145231286632397?lsf=seller:469699,store:6325541471639522064&prds=oid:4333583511621414874&q=embroidery+hoop&hl=en&ei=S9XVXL3UF7T59APJlKXoCw&lsft=gclid:EAIaIQobChMI3Jv8rt2R4gIVk_5kCh3Dig5oEAQYAyABEgJk9_D_BwE
My focus at the
present, is all outside surface work…will leave the inside
for later after the outside is tackled. Any idea if the screen
material (polyester?) will hold up to the solvent for
asphaltum? Jenny (
jtopolski)
pointed me at DYI presensitized screens that might be the
screen ticket so as not to have to go through applying
emulsion and all that entails. A tensioning jig, for the
embroidery hoop, to pull the screen onto the surface, should
be doable if the screen can be made to conform. * “Off to
shop and then to the lab”* as Dr. Frankenstein was
quoted.
When surrounding a bowl with a knit fabric held with an embroidery hoop, there could still be some wrinkling. Depending on the shape of your bowl, might there be areas that aren’t touched by the fabric? Would it be a problem when the mesh size varies …bigger when expanded and smaller when contracted as it fits to the bowl?
Oh that’s true! You could definitely try silkscreening asphaltum. I don’t know why that didn’t occur to me in my first post. 
Jenny, the issue with
screening, as I’ve now discovered, is the screen can’t be
initially resting in contact with the surface or the
ink/paint/resist will blob…so a screen would need to be
pushed and stretched over the surface to conform and most
likely would not leave a sharp image when it was lifted. Any
ex-screen printers out there to confirm?
I’ve only screen printed on flat surfaces but I’m not sure what you mean by “can’t be initially resting in contact…” For flat screen printing the screen is placed in contact with the carrier, paper, canvas, wood, whatever, ink is applied along one edge of the screen and then forced through the screen with a squeegee. The screen is lifted, the carrier replaced with a new sheet, the screen lowered and the ink squeegeed through again. More ink is added as needed.
The problem I see is with the faint impression of the screen itself which can be left if the medium is too thick. If you examine the art with a magnifier you can sometimes see a faint grid left by the screen mesh. This could be an issue if there are gaps in the resist where the screen mesh was.
Another thought on screening asphaltum: you might want to actually use “silk” as the screen, versus the polyester screen material that’s our there. The burn-in chemistry for the mask exposure… that needs to be VOC chemistry resistant. Otherwise, the screening ink/ ashpaltum gooo will compromise the design. When you go to clean the screen - removing the asphaltum with a turp or acetone, it would make a sublime mess. Use a water base mask on the screen.
Eileen