OIL AND BROMOIL 313 
should be immersed again in the glycerine solution at a tem- 
perature of 30° C. (86° F.), or until the ground shows a 
distinct relief ; then stick down again to the glass and ink up. 
It is stated that at least 100 pulls can be taken from this, and, 
of course, in any colour. The process is also applicable to 
three-colour work. 
