Yes, that's right! There is invisible part in the Art of Eftim Rusev.
Some of the used colors are fluoriscent. They are visible only after using a neon light. The effect is amazing! The fluoriscent colors are giving something like a second life of each painting and giving freedom to the soul of each piece of art. This is the limited edition called "Neon Line". You can literaly enjoy the painting even in the dark night.
Check the special effect captured in the dark, when the paintings is iluminated with tiny neon light.
You can find the additional images in section "Available paintings" of each painting where the special colors have been used, or you can see all of them in the Facebook Fan Page of "Eftim Rusev Gallery" here.