Lousy photo but I don’t have a good setup. In most cases, to highlight texture, I dropped wet paint on the texture once set, let it dry, then rubbed off the high points or painted them. With the exception of the middle right, the technique was to put a blob of paint down, then work it with a small clay sculpting tool until it began to set up.
The top row is mixes with Cuni medium and oil mediums, left to right: Williamsburg impasto medium, Natural Pigments impasto medium, Natural pigments Velasquez medium. I would give the edge to the two NP mediums, but they dry much more slowly, the Velasquez very slowly, that is not dry yet in 3 weeks. Probably not worth it when similar textures can be achieved other ways.
The middle row: Liquitex acrylic paint mixed with Cuni medium 1:1, Golden open acrylic paint mixed with medium 1:1, methylcellulose gel mixed with medium (pink) and MC gel mixed with nanoparticle titanium white/Cuni medium (blue and yellow – kind of hurried this one and messed it up; it looked very similar to the other before); various Cuni tube paints mixed with MC gel, trying to draw long lines out.
Third row: Liquitex with Cuni 1:2, Golden open with Cuni 1:2, Cuni yellow ochre straight out of the tube.
As mentioned, I don’t find the oil mixes worth the drying time. The acrylic mixes are both very nice, and possibly provide slightly longer open time and longer strokes than pure Cuni, but that may be a toss-up. Long and short handling refers to how long strokes can be drawn out before the drag of the paint breaks them. Cuni seems naturally pretty short in this context, at least for the kind of impasto I tested.
The methylcellulose mixes are very different. They make the paint sticky and give it a long, stringy handling that allows me to draw lines and drop them from the air a bit; quite interesting because it can be much more controlled than just flinging wet paint. Once down, they have a liquid appearance, and set more slowly than usual, allowing continued manipulation. The paint kind of melts a bit on the surface, so doesn’t lend itself to the churned-up texture of the other mixes. There are a lot of variables (dilution of the gel, type of pigment, ratios etc.), and it is interesting exploration. Perhaps rabbit skin or casein glue would be similar, but methylcellulose is very easy to make and is clear. I tried PVA glue but did not like the results. One of these days I will try egg. I assume work like this is safest on rigid supports.
I think in the long run I will use straight Cuni as much as possible for durability, but it is fun to see what can be done with these mixes