Multiple Layer Gum Printing

[Patrick Doyle]

Here is a link to a video I just had done to show how to separate film for tri colour printing.

Great video Bob. Could you show us the final print? I am dying to see the result of this.

 

[Andrew O'Neill]

Thought I'd go back and revisit gum over cyanotype for full colour gum... It worked out quite well. What did I learn? That my 3800 SUCKS for making digitised negatives. Grainy, and I just can't get rid of the banding. Thankfully the gum process hides it. I sure miss my 4000.

I think I'm going to take a look at the P400 that Sandy King talked about in his carbon group... Anyways, here is resulting print... on HPR.

 

[Bob Carnie]

Thought I'd go back and revisit gum over cyanotype for full colour gum... It worked out quite well. What did I learn? That my 3800 SUCKS for making digitised negatives. Grainy, and I just can't get rid of the banding. Thankfully the gum process hides it. I sure miss my 4000. View attachment 226936 I think I'm going to take a look at the P400 that Sandy King talked about in his carbon group... Anyways, here is resulting print... on HPR.

Nice print Andrew well done

 

[Andrew O'Neill]

..and now I have a P400 for making digital negs. Love it!

 

[Aimee Danger]

Like Christina Anderson, I will use water at the very end to bring out highlights in each layer and create local contrast.

Bob

Bob, I've never heard that. What do you mean by use water at the end? Are you saying you spray the image when the gum is wet to knock off gum strategically?

 

[himself]

After a long break from printing because of travel, I've just started working on some gum prints again, and I've been experimenting with different levels of gum, pigment(+gum) and dichromate and I'm having a bit of trouble with an unintended consequence.

Usually I try to keep my dichromate amount (and %) as a constant, but with the current print I'm working on I've discovered that for one of the layers, I really like the contrast when using a 1(8% gum) : 0.5 mix. This has basically meant that my coating solution is a bit thicker which is making it difficult to coat the solution.

So is there something I can add to the final mix to thin it out a bit without throwing off my concentrations, or do I need to add more dichromate with a lower concentration?

and finally, I hope everyone is staying healthy!

 

[Bob Carnie]

Bob, I've never heard that. What do you mean by use water at the end? Are you saying you spray the image when the gum is wet to knock off gum strategically?

Hi .. a bit late to this but yes this is one way a lot of workers create contrast within the image.. I use brushes and water.. If I want a tricolour image I do not do this, its more for duotone type images. or flicking in paper white with gum texture specular type highlights.

 

[Bob Carnie]

After a long break from printing because of travel, I've just started working on some gum prints again, and I've been experimenting with different levels of gum, pigment(+gum) and dichromate and I'm having a bit of trouble with an unintended consequence.

Usually I try to keep my dichromate amount (and %) as a constant, but with the current print I'm working on I've discovered that for one of the layers, I really like the contrast when using a 1(8% gum) : 0.5 mix. This has basically meant that my coating solution is a bit thicker which is making it difficult to coat the solution.

So is there something I can add to the final mix to thin it out a bit without throwing off my concentrations, or do I need to add more dichromate with a lower concentration?

and finally, I hope everyone is staying healthy!

I do not play with dichromate % differences... I do play with gum ratio and in some cases warm the water up for faster action but not sure if this is good for you , all our workrooms are different

 

[himself]

[...]I do play with gum ratio and in some cases warm the water up for faster action [...]

I tried that at first but unfortunately bumped up against the limit of the amount of gum/pigment I could add before it started to flake. But what I did do in the end was top up the dichromate volume with water so the final ratio of gum to dicromate was 1:1 (6%) instead of 1:1.5 (12%), and it turned out to have more or less the same contrast (as much as 2 prints can be he same anyway). The difference tho, was that with the same exposure time it developed to a level I wanted quicker.

So the conclusion I guess is, I'm not sure this would be a repeatable solution, but for this instance I did get the result I wanted : )

I think in future a better solution would be to keep my dichromate % as a constant as usual, but reprint a negative with a higher contrast instead.

 

[Bob Carnie]

I tried that at first but unfortunately bumped up against the limit of the amount of gum/pigment I could add before it started to flake. But what I did do in the end was top up the dichromate volume with water so the final ratio of gum to dicromate was 1:1 (6%) instead of 1:1.5 (12%), and it turned out to have more or less the same contrast (as much as 2 prints can be he same anyway). The difference tho, was that with the same exposure time it developed to a level I wanted quicker.

So the conclusion I guess is, I'm not sure this would be a repeatable solution, but for this instance I did get the result I wanted : )

I think in future a better solution would be to keep my dichromate % as a constant as usual, but reprint a negative with a higher contrast instead.

The role of the dichromate is to harden the gum with UV exposure.. I am not sure one should be considering it as a contrast agent .. that would indeed be controlled by the negative
and possible brush work on highlights to bring back the white..

 

[himself]

The role of the dichromate is to harden the gum with UV exposure.. I am not sure one should be considering it as a contrast agent .. that would indeed be controlled by the negative
and possible brush work on highlights to bring back the white..

I've read (not sure I remember where) that reducing the amount of dichromate can be used as way of controlling contrast, and I guess when we are first deciding what concentration to use, that's what we're doing to some degree... but you're right, I wouldn't consider it normally. There are already enough variables

 

[Bob Carnie]

I've read (not sure I remember where) that reducing the amount of dichromate can be used as way of controlling contrast, and I guess when we are first deciding what concentration to use, that's what we're doing to some degree... but you're right, I wouldn't consider it normally. There are already enough variables

This does not mix with my experience.. as its a wash off process that depends upon hardening of the gum through exposure.