There are various ways of coating the paper for salt printing. Up to now I have been brushing both the salt solution and the silver nitrate solutions.
A problem with silver nitrate is it can corrode the metal ferrule on brushes and brushes become contaminated very quikly. I find its best to use the brush only once. I even have problems when printing just a second print using the brush from the first print.
Rather then continuously replacing brushes, I make my own brushes out of inexpensive materials before I start each print. The handle is glass which is easy to clean and reuse, but the applicator is disposable and easy to remake.
All you need is:
An off-cut of glass, I would use 4mm to 5mm thickness.
A Glass cutter and a metal rule
Cotton wool pads
Score the glass to size using the glass cutter and metal rule. The size is up to you, I use 1 3/4 inches X 5inches. I made 2 glass ‘handles’, one for salt and one for silver nitrate.
Carefully snap the glass free, You should ideally use eye protection and pliers.
The next part is the only bit you need to replace after each print.
Take a cotton pad and fold it over the glass. The amount you use is up to you and needs some trial and error to form a personal preferene. I tend to use only half a pad.
Next cut a strip of flannel material big enough to cover all the cotton pad and wider then the glass handle.
Now tie some string around the top of the applicator is shown in the image.
Finally tidy up the excess material and string using some scissors.
With practice I find this brush can create very good results. I find that they absorb a lot of chemistry when you first use them, but this should be encouraged as I find nothing leads to worse results than trying to skimp on the coating. I tend to leave the brush sitting in a beaker of chemistry for a few minutes before I will use it. The amount of cotton padding used heavily influences how much chemistry will be absorbed by the blanchard brush.
For my next prints I am going to experiment with the glass rod technique instead. While the brushes are very easy to make; Im finding that for each print I need to make a new brush which can be time consuming. I am also no longer interested in the brushed edges of salt prints and want to try printing at A3 size which would be more of a challenge with the blanchard brush.