m. dowdall said:
Murray
It's not the most detailed description, but it does go through the basics.
http://www.alternativephotography.com/process_carbon.html
Michael
I should point out that the process described at the above site is carbon, not carbro. Carbon is a contact printing process that requires a same-size negative. Carbro, on the other hand, uses a bromide print (preferably made on a paper that is not super-coated) and a special senstizer to transfer the image.
Compared to carbon, carbro has certain advantages and disadvantages. Among the advantages are the fact that you don't need a large negative and you can dodge and burn on the bromide, which is easier than dodging and burning in contact printing.
Among the disadvantages the primary one is that for really highest quality work you must make a new bromide for every print, while in carbon the same negative can serve to make an indefinite number of prints.
Another big difference between the two processes is the fact that carbro has more or less a finite point of development, whereas a carbon print will continue to lose density the longer it is developed, within reason. This makes it somewhat easier to make exact duplicates of prints with carbro than with carbon, and this is the primary reason it was preferred in the old days for color.
I worked primarily carbro for many years and describe the working procedures very fully in my manual on carbon and carbro printing. However, I eventually switched to carbon because I like the ability to control density in development and on the whole I have found the chemistry of the carbon process is more reliable than the chemistry of carbro. However, Carbro is probably somewhat easier to work today than it was some 10-15 years ago as non super-coated papers, which had disappeared from the market, are now available from at least two different manufacturers.
In any event the final result is the same, i.e. a pigmented gelatin print, and Mac is a master of carbro printing who has obviously found ways to take full advantage of the process.
Sandy