Gum quality

The last couple of weeks I have been trying to make gum prints, but the gum would not come off. ( not even when using water instead of Kbichromate and not exposing before developing. ) I have been experimenting a lot and now think my conclusion must be that the gum I bought is not fit for gum printing. I am posting here, because I can hardly believe this conclusion to be the right one; does that exist?
When I dissolve 300 gram of this gum lumps ( very different in size and color) in 1 liter water I end up with a gum solution that has a viscosity of >>>>50 Baume instead of the 12.5 - 14 that should be. I have to add another liter of water to reach the needed viscosity. But then apparently I have a solution that is different in some way from the one needed?
Has anyone have similar experience with gum lumps?

Hi Nicole. There are bound to be some experienced gum printers here. Trying a commercially prepared gum is going to be the simplest way to test this hypothesis. You should be able to get a small bottle from any place selling art supplies. Where did you source the gum you have been using?

gum supplier

since I live in the Netherlands I purchased my gum from a paintproducing windmill ( really, I am not making a joke )
It is called Verfmolen de Kat ( paintmill the cat) Maybe gum for paint can be of lower quality?

Indeed I will try commercial gum when I encounter the same problems with the gum I ordered today. But when that high quality gum also will give these problems I will have to reconsider my workflow as well I guess.

Nicole Hagesteijn said:

since I live in the Netherlands I purchased my gum from a paintproducing windmill ( really, I am not making a joke )
It is called Verfmolen de Kat ( paintmill the cat) Maybe gum for paint can be of lower quality?

Indeed I will try commercial gum when I encounter the same problems with the gum I ordered today. But when that high quality gum also will give these problems I will have to reconsider my workflow as well I guess.

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Problem-solving is a huge component of alt printing Using a prepared gum makes sense, especially while you are learning the basics -- you will get a more consistent product, and this will eliminate a lot of variables that can create frustrating problems. Once you have a reliable workflow, you can play with more advanced techniques, but you will have a baseline you can use to better evaluate the results. If a prepared art gum doesn't solve the problem, then there is still work to be done ...

Hoi Philip,
From Christina Andersons book I got the impression that commercial gum could vary quite a bit in quality as well and for that reason she advises powder or lumps.
I thought: buying hashab acasia senegal gum must be the surest way to consistent quality. I understand from you, this is not the case?

Nicole,
In "Alternative Processes Condensed" Christina suggests starting with premixed gum (Photographer's Formulary, Daniel Smith, Bostick & Sullivan -- sorry, all in the US), and mixing your own as you become more experienced. I think this is good advice for any alt process -- focus on the basics, then move on to more advanced techniques after you have developed a reliable workflow. If all is well using a premixed gum, then you experience problems mixing your own, you will know that is likely the source of the problem. Best to eliminate frustrations when learning a process. Start with techniques and materials that are known to work, and experiment later. About quality: I would expect packaged products like gum and pigments to be consistent, though quality can vary by brand. This is less true of papers -- these often get reformulated with no notice, and the changes can have a significant impact on alt printing.

Hi Philip,
Thank you for helping me. I received the new gum lumps, did get a beautiful Amber colored syrup and coated two cyanotypie images with transparant yellow. The gum came off in the highlights !!!!!
I am in contact with the provider of the bad gum because I want to know if he can explain this big difference.

That's good news, Nicole. You probably won't get a satisfactory answer as to why the first gum was spontaneously hardening, but at least you have confirmed the problem and found something that works.