Mark,
Solarization can be a slightly greater problem with pure palladium, and when I started out, I avoided pure palladium because there were so many warnings about this in the books. However, I have found that will good printing skills, it is essentially a non-issue.
In an image, solarization can appear as somewhat anemic blacks. On the edge of the print beyond the negative, it will often look like the overcoat area is less dense than the the black areas in the negative, and is especially noticable in the rebate area of the negative right next to the overcoat area.
Rarely have I seen it actually start to ovbviously reverse density in the print, but that is essentially what is happening when a print starts to solarize. Just because you may get some solarization in the overcoat doesn't necessarily mean that you are getting it in the image, though, so minor solarization may not be of any concern.
Often a print will solarize a bit because too little solution was used in the coating of the paper. This will be much more apparent if you single coat the paper, and especially if you use a rod to coat, because a rod makes it possible to put the solution on in a nice even coat, but with much too little solution for necessary print quality. It doesn't pay to skimp on the solutions much.
Another issue is the proper exposure and development of the negative. If you heavily overexpose your film, and/or develop in a manner that creates a large B+F (many staining developers do this), you will require much more exposure than is required for an ideal negative. This will create a situation where solarization can become more of a problem.
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The Richeson brush should be used soaking wet, but not dripping. It is a completely different approach to the burshes the Dick talks about in his book. I think the Richeson brush is far superior, so I believe it is worth the cost of these brushes, as long as you are not abusive of your equipment. A $50 brush (for a 3") seems like a lot, but I have been using mine for hundreds of prints, and they are still going strong. There's a balancing act between too much water and just right. That takes some practice, but with a 2" brush, 4-6 strong shakes toward the floor works well for me.
Amazingly, if you do it right, when you go to wash the brush almost no solution will wash out, because it didn't absorb any. It doesn't take long to make up the cost of the brush in solution saved compared to the hake brushes discussed in Dick's book. They really are excellent brushes.
---Michael