Doing shading with etched enclsoures

[Taylor]

I've been wanting to do some etched enclosures, and in thinking about it, started wondering if it's possible to do shading. I always assumed that it's a monochrome process, because that's what everybody does. But my experience with etching PCBs made me reconsider.

When etching boards, sometimes the mask pulls off in a spot and you have to touch it up with a marker, of course. The first few times I did this, I didn't put enough ink down, so it got eaten, and the trace got etched some, but not as much as the copper that was exposed the whole time. So this makes me think that if you were to print a mask with some grays, the gray area would be a partial resist to the acid, but at some point it would get eaten through and the acid would begin to etch that spot in the box - but since the fully exposed parts had a "head start" they would theoretically get etched deeper.

Anyone ever try to do this? Do you think it will work this way?

[DerHoggz]

Possibly lots of little dots, might give a greyish look, but I don't know how well they would transfer.

Btw, are you perchance conical johnson from TB?

[KazooMan]

Taylor:

Interesting idea.  It might be easier to control by going the other way around.  Do a regular mask, etch for a while, and then mask off the areas you do not want to be etched further with paint or nail polish. 

[Taylor]

Possibly lots of little dots, might give a greyish look, but I don't know how well they would transfer.

Btw, are you perchance conical johnson from TB?

I am. I've been meaning to change my username over there to my real name - the one I picked 8 years ago as a teenager is not funny to me anymore. 

[Joe Hart]

I would think a half-tone (I think that's the term) thing would work. Like a picture in a newspaper. Lots of dots. Photoshop has options for doing this to an existing image.
-Joe Hart

[DerHoggz]

I would think a half-tone (I think that's the term) thing would work. Like a picture in a newspaper. Lots of dots. Photoshop has options for doing this to an existing image.
-Joe Hart

Yeah, that's what I meant, like an old-school comic.  But as I said, is the transfer reliable enough to get small enough dots?

[Slade]

Of course you can do it with the "dots" design method and a good control of the etching time, could be a little hard if you have no experience in etching enclosures, but you surely can if you do it carefully

[Taylor]

Right, I know about cross-hatching and halftone, but I'm wondering about actual solid shading.

I can't tell if this is etched or just a graphic, but this is the kind of thing I'm thinking of:

http://i33.photobucket.com/albums/d79/valerus/bass/sauron-1.jpg

Edit: it is in fact etched, so this is possible.

[Slade]

You can do that with etching, black painting and a careful sanding.

[soggybag]

You really to use a dot pattern or halftone of some kind. Most printers will create a half tone when you print. The problem is the half tone may be too fine for the medium. If the dots are too small they get etched away. You may be able to create a halftone in your image editor and adjust it to the density that you need. This might take some experimentation.

[mills]

I bet it'd turn out well by controlling the time it etches for, but might be way too much work to be worth it.  I know a few printmakers and had thought about trying something similar (although I'd pictured different supplies, your way is probably easier)... the way I'm picturing would still not be super smooth in the shading (unless you get really tricky and combine it with crosshateches/dots/etc).  I think I'd be inclined to do about 3 etches (maybe less time on each, maybe not) and progressively expose more of the box each time.

Also, I should be well past that point in life, "conical johnson" still kinda makes me laugh.