Pentalic produces many different types sketchbooks and their so called Watercolor Journal is one worth checking out.
The Pentalic watercolour journal features 300gsm coldpress paper. These were previously marketed as 100% cotton paper but there were questions about how true that was. And finally in late 2016, the 100% cotton label was dropped. So I'm still not sure if the original had actually used real cotton paper.
This watercolour sketchbook comes in two sizes, 3.5 by 5.375 inches and 5 by 8 inches (that's A5). It's a hardcover that comes with a ribbon marker, elastic band and back pocket. Corners of the sketchbook are rounded off.
The bright white paper is 300gsm coldpress. The paper is said to be from an European mill but there's no mention which one. Since the paper is thick, there are only 48 pages. The binding is stitch bind with glue. Paper is bound in six signatures and can open flat.
The binding is quite good, just that for those pages between signatures (e.g. groups of paper bound together), you may see some glue. If you don't draw across the gutter, it's not something to worry about. But if you do, then the work won't look as nice, but hey you're drawing across a gutter so the work will be cut anyway. It's not an uncommon problem for sketchbooks with thicker paper. Some of my 270gsm Stillman & Birn sketchbooks also have that problem.
There are some people complaining about the stitching but I personally can't see any fault with my copy.
Paper texture is nice and can create some beautiful granulation. It handles water well and in a controlled manner. The paper is tough and can withstand several layers of glazing. It's 300gsm so it does buckle even with heavy washes.
Check out some of the pen and ink watercolour sketches I've drawn in the sketchbook. I've used QoR watercolours for all the sketches below unless otherwise noted.
Waterfront of Fullerton
Neil Road and Craig Road intersection
Tanjong Pagar Rd. Daniel Smith's Cerulean Blue Chromium was used.
Duxton Hill. Daniel Smith's Cerulean Blue Chromium was used.
Chinatown. Daniel Smith's Cerulean Blue Chromium was used.
Toa Payoh. I tried some wet on wet techniques for the sky but I wasn't that good. If you notice for most of the sketches, I don't use much wet on wet techniques.
Painting and sculpting on giant clay balls at Thow Kwang Pottery Jungle.
However, there's something I don't like about the paper. Most likely it has got to do with the uniform pattern pressing of the texture. Perhaps it's also because the paper feels a bit like cards. Paper preference is quite personal. Perhaps it's because I've used other better paper.
You can find the Pentalic watercolour journal on Amazon. Unfortunately, it seems that this sketchbook is only sold in the USA.