I was asking because I have found the water based product Eco Print Shield to be excellent on all canvasses I have used to date but unacceptable on papers with the one exception, Hahnemuhle Fine Art pearl, which is a fantastic (expensive) paper. It accepts the Eco Print Shield beautifully resulting in an incredibly durable finish, however, the paper must be laminated to a stiff backing otherwise it will curl while drying. I have varnished canvasses and Fine Art Pearl prints hanging outdoors in full sun through two full years including Canadian winter that look pristine.
As to my experience with Eco print Shield on canvas:
I use an industrial HVLP spray gun on compressed air in a ventilated spray booth. Usually two coats. One wet coat of gloss, followed in 2 hours by a wet coat of Satin. For a satin or matte finish all undercoats should be gloss with only the top coat being the desired finish to avoid loss of print detail.
Many advise building up lighter coats but nothing works as well for me as two full wet coats – the resulting finish is flawless.
I dilute the product with demineralized water to a viscosity of 12 centipoise, spray prints horizontally and dry them stacked horizontally in a drying rack to avoid runs. A pressure regulator right at the inlet to the gun is set to 22psi – this will vary with different guns. I use a DeVilbiss EXL620 gun.
The water based product is great for cleanup and safety.