[alt-photo] Van Dyk sediment

[Harry Lock]

Hi All

Some time ago I bought a bottle (brown) of mixed solution for van Dyk prints. I used it and all was fine. Now I see there is a black sediment in the bottle. I have tried using the solution by pouring very carefully, as not to mix in the black sediment, and the prints look good.

My questions are:

Should I continue using the solution?
Should I try to mix-in the sediment, or put the lot through a coffee filter?
If the solution is 'working', as it is in my test, is the black stuff necessary, - or in this case - lack of it, effect the long term life of my prints?

Any and all help will be gladly accepted.

Harry