Tony et al,
I have become increasingly enamored with very smooth surfaces. I have also found the Claessen's (and a few others) are too slippery and greasy for me to deal with. Nontheless, I love the very smooth grounds they offer in terms of being able to really get tiny detail.
I now use the
www.NewTraditionsartpanels.com , L-600 pretty much all the time. Out of the box, it is way too slick for me. I have (compliments of Rob Howard,
www.studioproducts.com) now learned to work a first layer, be it toner or paint, in the Studio Products Underpainting medium. The medium dries almost immediately, and yields a surface that is uniformly matte, and that has a bit of tooth. It prepares a slick surface beautifully for the next coat of paint. I use it as well when I paint in oil, on Wallis paper.