As promised in an earlier post here are my comments on using Aquabord (clay board) for painting with watercolours compared to paper as the substrate. Above is a photo of a view of Harlech castle on an 11x14 inch Aquabord.
Before starting to paint I prepared the board by "flushing" the surface with clean water using a large flat brush; this is recommended to remove any trapped air. I allowed the board to dry before re-wetting prior to painting.
The paint does handle differently to the cold pressed paper I normally use when painting wet into wet. The "feel" of the texture was obvious to me in stroking the brush across the surface. Not very clear sorry - you will just have to try it.
The colours pool and blend in a way that they sit on the surface more rather than "sinking in" as with paper. Colours stay quite vibrant, but are better mixed in strong washes. When wanting to lift paint you have laid down it is easier than with paper. Colours may be lifted out while wet and quite easily when dry. In fact the board can be scrubbed clean.
One advantage of Aquabord is that you can seal your painting with an acrylic matte fixative and there is no need to put it behind glass in a frame. Unlike with watercolors on paper. So if you don't like your paintings behind glass due to reflections or colour change with UV glass it might be you will like painting on Aquabord.
The medium needs more experimenting with I think. My initial reaction after a couple of paintings was that I prefer the handling and effect obtained with watercolours on cold pressed paper. What are your feelings about Aquabord?