I have been curious to try Golden's OPEN brand of acrylics. These acrylic paints are supposed to stay wet on the palette and on the canvas much longer than traditional acrylic paints. I was shocked that they were still Wet on my palette the NEXT day! No retarder... Nothing used to extend paint life.
On the Canvas board, I applied thin coats as suggested and was able to blend them together like oil paint. I was surprised that the paint remained tacky and rework able even though hours had passed.
So far, the colors are just as vibrant as heavy body paints, but the paint itself is thinner than the heavy body. This is fine by me since I thin my stuff down anyway. The price is about the same as regular paints :)