I am painting a trompe painting with currency (a bill) in it, and one of the anti-counterfeiting measures is the use of optically variable ink (ovi). Basically, it is ink which changes color depending upon the angle at which it is viewed. I wanted to simulate this effect with my painting, but I don’t know if that is possible.
Possible approaches:
Get some OVI pigment/ink/paint. I looked into OVI, and my initial search only turned up (expensive) sales on alibaba.com or other Chinese online sources, but I didn’t find any available in the US. Anyone know of color-shifting pigments or paints (shifts color with viewing angle)?
Mimic the OVI effect with regular paint: Is it possible to mimic this effect (maybe not as well) with successive applications of regular paint? I’ve been experimenting with a little success, but not much. Anyone have experience with this?
Not even try: Just present the color that the straight on viewing angle of the scene gives. I know I can do this.
While I cannot say for sure regarding the exact bill you are using—but I think you are looking for an “interference” color paint. Interference colorants consist of various layers of a metal oxide deposited onto mica (could be titanium or iron oxide). Light striking the surface of these paints is refracted, reflected and scattered by the layers that make up the colorant. Through a superimposition (or interference) of the reflected rays of light, a changing play of color is created, with the most intense color seen at the angle of reflection.
The perceived colors elicited by interference colorants are dependent on the angle of observation and illumination, and they will alternate with their complementary color as the angle changes.
I have actually used this type of paint before with success. I used it for a stamp of a horse in a piece with a Wizard of Oz theme. At different angles the horse would appear to change color.
Williamsburg makes a number of such colors in oil.
Thanks for the feedback Anthony and Jeffrey. Were you guys pleased that you did it on the paintings?
I’ve wondered if it will come across as gimmicky, or if it will look nice and natural. I guess it depends upon how much and how “normal” it looks for the object, like Jeffrey hinted at.
And I haven’t used the paint since, so there’s that too
I say give it a try - if you don’t like it, you’re only out the cost of a tube of paint, and you can paint right over it. The only thing that matters is the final result.
For me it was a very subtle component in a complex work so it didn’t jump out as a major gimmick (although I could see how some might see it that way if it was center stage). I am happy with how it worked in the piece—and if the right context presented itself again I would use it without hesitation.
