These days we are seeing more and more natural media simulation being attempted in digital painting software. One of the most difficult to achieve is watercolor, because there are so many variables and physics to take into account. Until now, we've seen some good attempts for western watercolor. Expresii makes the case for Eastern Ink painting on rice paper. And it does it great!
The look and feel of the UI is not the sexiest I've seen, but it gets the job done. You have to explore and play a little to see that even though it seems simple, there are many options and tweaks you can make use of. I recommend you read the User Guide after the first moments of play.
After playing with it a little I can honestly say this is one of the greatest painting programs I've tried when it comes to how it feels and how it renders what you do. It truly feels organic. It is a pleasure to play and paint with it. But this achievement is complex stuff, programming and calculating so many of the real world's variables.
Using the Moxi paint engine, Expresii brings real-time fluid dynamics into digital painting, adding further enhancements to its algorithm. If you have a device with accelerometer, you can tilt the device in order to make the paint run in gravity's direction. You can add strokes, tilt the surface while the flow is still running, all in real-time.
The Yibi brush engine lets you see the brush shape as it makes contact with the paper to know exactly how the stroke evolves. It was designed with the stylus in mind, primarily for the expressive strokes used in Eastern art. The brushes rely heavily on stylus tilting, so it's strongly recommended to use Expresii with a device that supports this.
There are two types of brush: Flow and Needle. The Flow deforms like an Eastern brush, while the Needle is non-deformable and thinner. Also, the tilting of your stylus will create a truly great variety of strokes, as in real life. This is where Expresii shines.
One thing that's different from all other paint programs is the fact that you always paint with a gradient. This is the way it's done in the East. It is very cool, and you can get a very realistic feel if you make a gradient that behaves like real paint, and some great effects with multiple colors. On the other hand, it takes time to get used to when you just want one flat color to paint with. See, you load color from the color tab with pressure -- the more pressure, the more color you load. This behavior feels strange at first, but like with everything new, the more you use it, the more natural it feels. There are also quick ways to lighten a color and hotkeys to assign up to 10 gradient presets, which is very handy.
The Youji Rendering Engine makes it possible to zoom in deep, and keeps a level of details that it feels like you're really getting closer to a real piece of paper. You don't get pixelation. Instead, it's like you are using a camera with a macro lens. Great stuff.
The greatest of all, though, is just the painting. How it deposits, flows and interacts with the canvas, the moisture levels and itself, is amazing. You have control over a lot of variables, like paper texture and granulation (in real watercolor, different pigments give different levels of granulation); how the borders of the wet paint behave, like roughness, darkening (this also happens in real life watercolors), absorbency; how the paints flows and its viscosity. An amazing set of very specialized features.
There are many more things you can do like use a background, a reference image, change the paper texture, tint it and many other things. Expresii explores one type of painting, but with so many options and controls, you can't help but fall in love.
It makes extensive use of the GPU, so make sure you meet the minimum hardware requirements. Also, there are lite modes, so you can use it with less features on older hardware.
All in all, I'm in awe at this creature. It feels and works great. I cannot recommend you try this enough.