There were a few things I learned as I watched the demo listed below.
First, Barry mixes his own mixing white using titanium white acrylic paint and acrylic paint retarder in a 3:1 ratio. The mixing white is used to tone the colors on the palette. This does two things, one it extends the drying time of the paint and two it tones down the intensity of the paint (acrylics tend to dry darker).
Barry adds the retarder to a mister filled with water. The paints on the palette are given a fine mist periodically so that they don't dry out too soon. The mist can also be applied to the painting to aid in blending the colors on the surface.
![Palette Garage (12 Inch)](https://images-na.ssl-images-amazon.com/images/I/41kuMFNhLgL._SX425_.jpg)
Barry uses a Palette Garage to store his paints between sessions. This can be obtained at Amazon for around $28.
I found that I can store paint by using the Premier Paint Palette by Nicole, that I got from A. C. Moore for around $20. Other brands/styles similar to this can be found on Amazon starting at $10.
The Paint Palette is air tight. I added a moist paper towel and found that the paint stayed workable for several days.
The Paint Palette has a removable tray for easy cleaning and adds an extra mixing area.
I added some Golden Open extender to a mister. I use this to occasionally wet the paint on the palette during the painting session and as a final wetting when done for the day.
I used a combination of Golden Open and Liquitex Heavy Body Acrylic paints on this painting. Both worked well with the mixing white. The Heavy Body stayed just as moist as the Open acrylic during this testing time.