AFAIK, the difference is that the polyurethane varnish is more durable & dries quicker. But can the polyurethane varnish be thinned with water or acrylic thinners? Does it yellow or brush well?
Waterbased Acrylic Paints 500ml bottle Non-Toxic Non-Flammable Designed for use when plastic modelling
Vallejo Model Color 500 ml Gloss Acrylic Varnish
Varnishes – Turbo Dork
VAL26657 Gloss Metal Varnish 60ml (2.02 Fl. Oz) Jar Vallejo Paints
Waterbased acrylic varnish with new, quick drying formula, and an acrylic resin of extraordinary hardness and permanence. Protects painted models from dust and scratches, dirt and humidity. Acrylic Varnish should never be applied until the paint has dried completely (see note), and it is recommended to wait at least 24 hours. Varnish should be applied in fine coats at approximately 5-10 minutes intervals.Presented in a 60ml bottle with flip-top cap.
Vallejo - Satin Acrylic Varnish (60ml)
Kriegs Corner: Vallejo Matt Varnish Disaster and Redemption!
Vallejo Model Color Colour Gloss Glossy Varnish 26517 60ml
Vallejo Acrylic Paint, Gloss Varnish
Varnishes – Turbo Dork
Vallejo Mecha Color - Gloss Varnish 60ml – Pandemonium Games
Vallejo gloss varnishes: what are the differences between each of
Vallejo Polyurethane Varnish
What's the difference between these Vallejo varnishes? - Paint