Koval is a company founded by Tomasz Kowal in Poland that specialises in making watercolour sketchbooks that uses cotton watercolour paper.
The line of sketchbooks are called Sketchbook Pro. The sketchbooks use Arches, Arches Expression and Fabriano Artistico paper.
They are available with different cotton content (50% and 100%), surfaces and paper weight.
The sketchbooks that I've received from Tomasz for this review are hardcover sketchbooks that come with the corners cut sharp.
The hardcover is made of veneer that looks like leather. The surface feels slightly rubberised and seems durable. The covers are available in black, gray, dark blue, white and pink(?).
Each sketchbook has all the details of the watercolour paper written on the front.
The sketchbook comes with a wide clothed elastic band that you can use to strap your tools together with the sketchbook. The band can also be used to keep the paper flat.
These are some ideas on how you can use the elastic band. I like the fact that the elastic band is not stitched to the sketchbook. Such elastic band usually lose their elasticity with time so it's great to know that when it does happen, the band is not stuck to the sketchbook.
The binding looks good. Each signature has two pieces of paper that makes up eight pages.
The binding allows the sketchbook to be opened flat.
The first and last pages are glued to the endpaper of the cover though, so those are the only pages that can't open flat.
Shown above are some pen and ink sketches with watercolour. The paper in this particular sketchbook I have is Fabriano Artistico with 100% cotton 300gsm watercolour paper. The quality of this paper is fantastic and it works great with watercolour.
Sizing of the paper seems fine. Ink dries fast. Water dries at the usual speed. And watercolour paint is able to remain on the surface of the paper so transparent colours appear vibrant.
Even though this 300gsm paper is thick, alcohol markers can still bleed through the paper.
Gouache works fine on the paper.
There's some watercolour that has seep through the binding to the page with the gouache.
While the binding is tight, water can still seep through if you use too much water.
Wet on wet techniques are possible but not as good compared to Arches watercolour paper. No good in the sense that paint does not move as far on wet surfaces, and when charging in paint to a wet surface, the blend is not as soft.
The coldpress surface texture is a bit rough for coloured pencil use.
These are mechanical pencil lines.
Glazing or layering works fine. But do test the paper with your paint first. I painted Phthalo Blue, a staining colour, and allowed it to draw, and it was reactivated when I painted the yellow over it.
Overall quality of the sketchbook is top notch.
At the time of this review, the price of these sketchbooks start from US $39 and varies depending on the paper used.
Find the current price and all the different types of sketchbooks at https://kovalshop.com