Strathmore 300 Series Watercolour Paper (300gsm) is a student quality budget paper.
It's very favourably rated on Amazon.
There are many other types of paper in the 300 Series, such as Drawing, Bristol, Tracing, Newsprint, Sketch, Printmaking and possibly a few more.
For the Strathmore 300 Series Watercolor Paper, it's available in gummed and spiral pads.
It's a cold press paper but the texture is rougher than other cold press papers I've used. Also there's this horizontal pattern going across the paper. The other side of the paper is much smoother.
The paper has a lot of tooth. If you're using pen or pencils, the tip will go into the grooves.
The horizontal texture pattern can sometimes be distracting and call out for unwanted attention. This is definitely not the watercolour paper to use for commission work. You'll never know when that texture pattern can work against you. Personally, for cold press, I prefer fine grain texture, the sandy type.
There's no mention of the material the paper is made of, so it's most likely wood pulp, and it feels like wood pulp too. As with those wood pulp paper, it's not recommended to use too many layers or the paper fibre will come off. The 300gsm paper is quite strong and does warp much with water, but usually I'll still clip it down.
Here's the scan of the sketch above. The paper is very white and it brings out the colours vividly. I was using Daniel Smith watercolour paints above.
The paper is not particularly absorbent so your control of watercolour should be just right. You do have some amount of leeway as water doesn't pool that easily, which is great.
The two pictures above are photographs and the scan is below.
This was painted with Winsor & Newton watercolours. I don't particularly like the granulation pattern caused by the paper texture.
This was painted with Sennelier watercolour pan set. I feel the paper works well for less granulating paints.
Another piece painted with Sennelier. Again, I don't quite like the paper texture as shown by the sky area. It doesn't feel right.
For practice purposes, the Strathmore 300 Series Watercolor Paper is decent enough. It's affordable which is great.
My main practice paper is Daler Rowney Aquafine which is slightly cheaper because they are available in 50-sheets jumbo size pads. I also prefer Daler Rowney's Aquafine because the texture pattern is less obvious than Strathmore 300 Series.
Search Utrecht Art Supplies (USA) too.