Re: more gum
I have very little experience in gum printing as well(!), but I was following those same directions-- and I did not have good results. This went on for a while, until I started emailing people. I did discover I was exposing the prints for too long (part of my problem), so I shortened the time significantly, and it got a little better-- but still weak looking prints. A little later, it was also suggested to me I was using too much dichromate and gum for the size prints I was coating, so I cut way back. About the same time, I also switched to glut instead of glyoxal-- and that made all the difference.
Since I made those 2 changes at the same time, I'm not sure if just cutting back on the dichromate and gum alone would have fixed my problems. I do know that following those exact same directions, I was using too much dichromate for sure-- as well as gum. Also, I know people have discussed here about the effects of humidity (too much or too little) on gum printing. I actually keep a humidifier in my darkroom, and *always* have better results with any alt printing when I use the humidifier. The coating goes on more evenly as well. I'm in the South, but it must be very dry in this house. I have also used the roller method that Kerik taught in his gum over platinum class (instead of a brush), which eliminates uneven coating as well. If I humidify the paper ahead of time, though, using a brush seems to work fine, too.
I am also very new to gum-printing, but I just went through all that-- and those were my problems. I'm sure I'll face more, but making those two changes improved things significantly for me.
On Apr 7, 2008, at 6:33 PM, Weber, Scott B wrote:
I have very little experience in gum printing and one of my students has decided to print gums. She bought the gum "kit" from Bostick & Sullivan and followed the directions in Chris James book for glyoxal-gelatin coating to size the paper then used the 6ml gum, 6ml pot. dichrom (10%) with about 1/2 inch of watercolor pigment to sensitize. Starting with a digital neg chosen by exposing the color density range palette from PDN she arrived at a negative which is sort of orange. The resulting images are weak and the coating is very uneven. This student knows how to coat paper as she produced excellent prints in my class with cyano and VDB's. She is frustrated and I said I would try to help. From my description does it look like we are doing anything wrong? I know many of you are excellent gum printers maybe through your experience you might see something that she is doing wrong.