Syrian rue and fluorescence

[murklan]

I'd wondering about how to get a stable pigment that can be used for painting or dyeing that uses the strong fluorescence of Syrian rue. Has anyone made and used some pigments with it? A water extract stains wood, skin etc. But what about the dry extract and to make that into a paint that is not dampening the fluorescence?
I think the fluorescence is dependent on Ph also, but I don't know more. Somewhere I read that for using Rue for the Harmala red that has been used for dyeing fabrics (for mats) it needed to be acidic.
I also wonder about the best wavelength for the UV light for strongest effect. I have both 395 and 365 uv lights.

I've also seen that this has been up on the forum before:
harmala alkaloids and UV light

 

[blig-blug]

I have absolutely zero clue if this makes sense, but this idea comes to mind: how about mixing harmalas into transparent varnish? I don't know how long that would last, if it works, but it should be easy to do a small test.

 

[Transform]

I have absolutely zero clue if this makes sense, but this idea comes to mind: how about mixing harmalas into transparent varnish? I don't know how long that would last, if it works, but it should be easy to do a small test.

Good point. The main problem with using a (nominally) soluble pigment is how to fix it. The subject of fixatives is a fairly large one, but for harmalas I can come up with three fairly practical approaches off the top of my head.

• If there's a really insoluble harmala salt, one could use the relevant acid as a fixative before or after applying the harmala design;
  
• Harmala freebase could be applied as a solution in alcohol, or;
  
• A colourless metal cation could be applied, as in mordanting of dyestuffs, but I'm not sure which one might be best for this. Tin II chloride has been used for mordanting numerous other natural dyestuffs.

A less practical method would be chemically derivatising the harm[al]ine so that it can form a permanent bond to the substrate, as in the case of reactive dyes. These usually use cyanuric chloride to achieve that purpose, so I don't think it's necessary to go into further detail there.

 

[murklan]

Good suggestions! The transparent varnish need to be UV-transparent and usually that is a bad thing since you want to protect the surface and/or pigment against the sun. But I don't know really, perhaps most are UV transparent. I've tried PVA glue for wood that dries transparent. Not great result.

Interesting @Transform ! I'm also curious for dyeing and have grown shitloads of Japanese Indigo in the greenhouse this year. Dried it all now and waiting for some good use. I didn't know about metal cations. And yes cyanuric chloride sounds... a bit to far even for my curiosity