Hello LyS K MUsIC , that is the Fabric what is included in most of the Kits, in this Case it's the Amati Hunter Q Ship Kit. I also have tried Painters Canvas, but it's a little thick and I am not sure if there are thinner Painters Canvas available. If so, that can be used too. One more Tip, or call it Update, instead the PVA Water Mix you also can use Acrylic Matt Varnish from a Spray Can, that works too and also faster .

Liutauras Grybauskas thank you, glad that I could inspire you.