Dear Donia,
How do I remove the smell of mold and mount and frame watercolor paintings?
Q. Dear Donia,
A. Dear Laura,
Thank you for your excellent question! There are several ways to reduce or remove the mildew odor from watercolors that won't be damaging to the artwork. We will start with simple and inexpensive using materials that should be easily procured in Italy (how wonderful to live in such a lovely country!). Put the watercolors in a clean plastic storage container with bowls of baking soda and then put the top on the container. This process will take at least a year. A question that usually comes up with this method is how often to change the bowls of soda. Frequency of change and the overall length of time to reduce the odor is all based on how much baking soda you are using, how much surface area of the baking soda is exposed (shallow bowls expose more soda and work more efficiently), how many watercolors you have, and just how smelly they are. In any event, I would follow the guidelines on the box which is to change the soda every 30 days. This should help to absorb odors more efficiently to help you complete the project more quickly.
You can also use activated charcoal which you can get at a pet store. Activated charcoal is used in fish tanks to keep the water clean and it is also great at absorbing odors. You would use it in the same manner as baking soda but don't need to change it as often (about every two months). You can also try the Gonzo Odor Eliminator rocks that you can find on Amazon. If you purchase a couple of these, you can be recharging one while you are using the other. Again, change out every 1-2 months. I would avoid the odor absorbers you can find on Amazon or in the stores. These often have chemicals that release "pleasant" odors and these can be damaging to your watercolors. It is best to stick with baking soda or activated charcoal.
A more expensive but more efficient and gives overall better results in my experience is MicroChamber paper. If you get some MicroChamber interleaving paper and place as many watercolors on each sheet as you can without overlapping making a stack as you go along you can put this stack in a plastic storage container with its lid on. Change the paper out after one month and each month after that until the odor is gone. Conservation Resources has an office and warehouse in Oxford, England so ordering from them should be more cost effective than ordering from the U.S.
When it comes to framing your watercolors, be sure to look for a framer who will use archival mat board and techniques. The best mat board to look for is what we call museum rag board. It comes in many shades of "white" and you should have not trouble finding one to match your watercolors. Whether your are going to a framer or you are doing the matting and framing yourself, please take a look at the helpful leaflet from the Northeast Document Conservation Center on "How to Do Your Own Matting and Hinging." This helpful guide will let you know how to best mount the watercolors so they will be safe for generations to come.
As for the glazing, you will want to look for glass or Plexiglas that has UV blocking properties. TruVue glass and Acrylite plexi are two examples. Choosing between glass and plexi depends on what you want. Glass will be clearer, hold less of a static charge, and be more resistant to scratching but is heavier and not recommended for areas prone to earthquakes.
I hope this helps and if you have any more questions, please don't hesitate to ask Dear Donia!