Parallel Rainbow

I worked (and still work) with fountain, and parallel pens. Many of them were simple, others were colourful. I loved to organize my pens, and the colour was the main criteria.
This is a rainbow-like graphic inspired by my tools, more specifically, the parallel pens. Maybe I use this for a calligraphic specimen, or as a promotional brochure, but for now, I am going to call it the "Parallel Rainbow".
Nib widths, from top to bottom: 0,5 mm; 1,5 mm; 2,4 mm; 3,8 mm; and 6 mm.