Is it true that canvas printed with eco-solvent inks don`t require an overcoating?
Yes, they are incredibly durable. You can scratch at them with your fingernails and not damage them.
Then why use anything else?
That's what solvent printer owner think. :-]
Is the eco sol printer capable of matching the gamut of pigment printers?
Pretty much - very nearly so. And the new inksets have light blacks and colors so you don't see printer dots. Solvent printers have a higher cost of entry and require RIPs so they aren't consumer printers. While the quality is comparable to aqueous inks on canvas, aqueous inks resolve finer detail on matte, RC and fiber base papers, so most solvent users use them on canvas or other outdoor substrates like vinyl.
The supplied profiles that come with RIPs for these printers are surprisingly bad. I'm spending a lot of my time traveling around the country making profiles that are far better. Solvent ink calibration is particularly tricky and the color science in a lot of the RIPs is pretty lousy. I've developed a methodology that allows me to find the perfect per channel and total ink limiting as well as generate a set of Lab based curves, regardless of what printer and RIP I'm working on. So creating the optimal calibration prior to the profiling process is the key to excellent results on solvent printers that so many struggle with.