SketchBlock App

  • By
  • On 3rd April 2015

SketchBlock App Delivers Digital Paint

Out of a welter of digital drawing and painting apps I have just discovered another – and a very good one. SketchBlock  by Nguyen Tan Hon-Hu has been available since 2013. Woe be it that I am seldom in the vanguard of all that’s new on the digital software scene. That may be extended to most things in my life – I’m usually the last to know or be in the know.

Yesterday I gave SketchBlock a tryout in the painting below. As a traditional media oil painter, I am always searching for any digital app which delivers a believable oil paint surface. SketchBlock joins ArtRage and Art Set Pro in fulfilling that search. Though not quite as “painty” as ArtRage, SketchBlock has a set of good working Oil Brushes which I would rank among the best of any digital or digital mobile app available.


There are three excellent Oil Brushes on board SketchBlock. Let’s begin with the basic Smooth Oil Brush below. Each set of yellow-red-blue shows the paint application at 25% and 100% opacity respectively. I have chosen an on board rough canvas texture for the demo. You can see that the overall coverage is uniform allowing the textured canvas to show through the less opaque or more lightly covered areas.

sketch block app

Smooth Oil Brush


The second brush is the Smooth Graded Oil Brush. This brush and its companion the Rough Graded Oil Brush have special characteristics which I find in many ways more useful than either oil paint brushes in ArtRage or Art Set Pro. The decided advantage of being able to grade the paint stroke from lighter to darker and from brighter to duller helps you to create modulated changes in surface at a single stroke. This means you don’t have to keep applying new strokes of added color or tone to get the transitional effect you are trying to achieve.

It’s interesting to notice that the pigment applied at 25% opacity runs very quickly to dark. At 100% opacity, however, the transition is much slower.

sketch block app

Smooth Graded Oil Brush


The third and final brush of the oil paint brush trio on board SketchBlock is the Rough Graded Oil Brush. For me this is the “grabber” of the entire suite of tools in SketchBlock. You will notice the transition from light to dark is much slower than the Smooth Oil Brush above possibly due to a heavier layer of pigment. This feature is useful for working on larger areas when you don’t want to raise your stylus or finger to fill that area.


Of the suite of three brushes, I find all three useful. The 2 graded brushes appear to get darker by the addition of black. I would appreciate some tweeking by the developer in which a complementary color could be used to achieve both the darkening and graying effects. I look forward to working further with these fine brushes from this very well produced digital app.

sketch club app

Rough Graded Oil Brush


Earlier I mentioned using a rough textured canvas as the ground for these demos. Another feature which I want to commend is the Eraser Tool. With many apps when you erase, the eraser cuts through whatever surface ground you are using and reveals the blank white trail of the erased area. With SketchBlock, the full integrity of the ground underneath remains. This is very useful for revising areas of a picture. This is useful for working into large areas with a single color without having to lift your stylus or finger. By adjusting the opacity slider of the Eraser Tool, you can also vary the amount of digital paint which you want to remove – almost as if you were daubing a wet oil paint surface with a rag.

sketch block app

Eraser Tool


So that’s it for now. Give SketchBlock a try and, as always, I am eager to know of your experimental findings.

Please leave any comments you’d like to share and Subscribe to this Blog in the Subscribe Box upper right.