My glass slide carrier isn't dirty and I checked the slides and no probs. with dust spots or anything. Still, when I've run off a 16" ilfochrome, I found a small speckled appearance in part of the image.
Knowing the ilfochrome surface, this is probably a no-goer and I should probably just reprint everything.
Is there a reliable spotting process for ilfochromes which matches the gloss surface?
When I was doing an independant study in color printing at a lab that did primarily Ilfochromes, their Ilford rep got exited when he heard they had a few of us learing the process and got us a ton of literature, among that was some instructions for spotting. IIRC (it's been a little while and I didn't read that part too carefully) the basic idea was to bleach the dyes in an area, and use color spoting dyes. We were taught to just reprint anything with dust though, and as far as I know that's what the lab did for their clients' work as well. If you've got access to anyone who could get you the literature from Ilford (acctually Ilford would probably send it to you directly), they've got some great information about everything from the chemistry, to masking to retouching. If you can't get ahold of it and would like to, PM me and I'll see if I can find it and scan it for you.
You didn't say whether they were black spots or white spots. The Ilfochrome spotting dye set is the only thing you can use on that surface. Whites spots are really quite easy to remove.
What I do is use a small, plastic, watercolor pallette with little dimple wells around the perimeter. I use a large brush, wet a spotting color and put some of the dye into the well. Clean the brush and do that for each color. Let the dyes dry in the well so they're solid again. Use a small spotting brush, wet the brush, pick up the colors you need and mix them on the flat pallette area. Mix them slightly lighter than you think the color really needs to be. Spot the area with a light stipple pattern just like you would with a black and white print.
I like to use distilled water for the dyes as it will not leave a residue on the surface. You have to make sure you don't get the area too wet or you'll leave a ring around the area you're spotting - try to be as "dry" as possible.
Now for black spots - a real, royal pain. They have to be bleached out and then spotted back in. This is really difficult because the bleach has to sit on the surface long enough to remove all of the dye making up the black spot. Invariably, what happens is the bleach spreads very slightly as the emulsion swells - and you end up with a bigger white area that needs to be spotted.
If this is a large area or lots of spots, reprinting is far, far faster.
Peter and Steve -
That's so helpful. I've revised what I know about spotting today. The ilfochrome spotting kit is something I didn't know about - I'm looking forward to working with a dedicated piece of restorative material.
It feels like a shame to waste a print on the grounds of a few spots (bad news Steve - they're black). I have to use a watchmakers lens to do the spotting and also get the coffee brewing to calm my nerves - feels like a lot of work but if the gloss can be matched I'll be more than happy about working with my ilfochromes. Thanks for the suggestion Peter - I'll have the joy of asking Ilford a question they may be able to answer