Proper way to varnish acrylics, never noticed this before

[Terry Hart cpf]

It's just come to my attention that both Liquitex and Golden (not the brands of varnish I usually use) reccomend first varnishing an acrylic with water based gloss polymer varnish as an isolation barrier before varnishing with a solvent based acrylic resin varnish. I find no such reccomendation from Gamblin or Winsor Newton.
What do you think. A good idea for the art or for selling more product?

 

[beerhere]

Hello Terry.
My simple thought is that a polymer would be a harder surface than a solvent based acrylic.Therefore offering more protection in the future from doofs like me trying to clean a painting with something like acetone or ketone.
(No its never, nor will it ever happen).

BTW- Will be posting photos of that cathedral-arch top frame I had asked you about last year. Finally rec an approval on it in January and I'm close to completion, hopefully this weekend.

 

[Terry Hart cpf]

Well, the solvent based polymer resin should dry to a harder film than the water based. The only thing I can think of is that the acrylic painting is porous so the varnish will soakinto it to a certain extent making it impossible to completly remove so the initial isolation barrier of water based would (possibly) allow complete removal of the solvent based varnish? I'm not sure what Liquitex and Golden really have in mind. I can think of several possible problems with this line of reasoning. Maybe they just want to sell more product? I'm curious what Rebecca or Hugh might have to say about this.
Looking forward to seeing the pics BH. Spring is here! Make mine a nice hoppy IPA! I've got one batch bottled already and one in the secondary dry hopped with an oz of Goldings plug. Win Twins!