I'd say MANY prints need to be spotted. When I print 35mm negatives, I try to be so careful to blow away all dusts but inevitably, some get left behind. Because magnifications is so high, a tiny spot becomes visible blotch. Those need to be spotted as they attract too much attention. Sometimes, film imperfections like dried on particles becomes problems. They need to be spotted. My criteria is, if the defect is large or offensive enough, they get spotted. If they are in innocuous area or very small, sometimes I leave them alone.
Originally Posted by stradibarrius
Palette with many holes
I find 000 brushes most useful. 00000 brush less useful but nevertheless essential. Buy good to great brushes - no bargain brands, please. It is absolutely essential that tip of the brush holds together. Also, be very careful and use these brushes only for spotting.
What I do is, a day before spotting, I put a small amount of (a drop or two) dye on two places in the palette. Then add few drops of water. Let it dry over night. It spreads and makes a patch of very thin coat of dye. Next day, I wet my brush very slightly and dab on the dried area to pick up very small amount of dye. I do some trial "spotting" on a sheet of paper (I find envelopes junk mails come in great for this purpose!) until the density is little less than just right. Then spot the print. Repeat this process until I'm satisfied that spot no longer attracts attention. The density needs to be built up by repeated application. This method is so much easier than diluting the dye to match the tone.
The goal is NOT to paint the fault entirely or it has to match exactly. You'll be amazed, a dot in the middle of white area takes attention away from the blotch. If you stand a foot or two away from the print and you can't find it, you are DONE. If your dot is too strong or too dark, it will attract attention, so it is essential to use small dots and less density.
Next time you go to a museum, examine prints very closely.... you'll be amazed how "imperfect" of a spotting job great prints have.... yet, at distance, they blend in. That's all we need.
It's a lot easier than it sounds. If you make a mistake, just wash the print and dry, and start over again. You'll get a hang of it after few times.
I'm fond of the SpotTone spotting pens - others dislike them.
Make sure you have excellent light - even, diffused, of good intensity and reliable colour.
Too little is much better than too much.
Tiny spots laid down in a figure 8 pattern fill up an area better than any attempt to lay down larger amounts.
Matte or semi-matte paper is your friend.
And make sure you don't mistake details of the scene for dust and mistakenly spot them out.