Here you see the same onion, I painted with the same colours (Schmincke Horadam water colours) only from different perspectives and on different papers: Arches hot pressed paper (Grain Satiné) on the left and Arches cold pressed paper (Grain Fin) on the right. They are both premium cotton papers and have the reputation to be one of the best papers on the market.
You can see very well, how the papers differ, the cold pressed paper has more texture and a rougher feel to it. The hot pressed paper on the other hand has a very smooth, velvety surface.
And you can also see, how the completed paintings differ. You can recognize every tiny detail on the hot pressed paper and the colour stays more on the surface of the paper. The downside is, you have to be very careful when you paint, because every brush stroke stays visible and the washes tend to have hard edges. On the cold pressed paper you can achieve smoother washes and the colour sinks more into the paper. But details are less easy to paint and all the edges are softer.
In conclusion, it’s a good idea to think about the subject you want to paint beforehand. Do I need large washes or do I want to paint a lot of small details? Depending on the answer you decide if you choose the cold or hot pressed paper.