Chroma Atelier Fast Medium/Fixer 250ml

It works well at sealing the painted surface however it does have a notable sheen. I'm not totally convinced by the Atelier interactive acrylic paint product, even the titanium white is slightly transparent, not what I am used to with either Liquitex, Golden, or W&N Artist, all of which have an opaque finish enabling solid coverage even over vivid and high contrast under paint.