I'm thinking about buying a Surface Studio to mainly pratice Vietnamese and Chinese calligraphy. I'm using Procreate and Zen Brush 2 on my Ipad Pro now and they are pretty good. Do you know any Windows apps or software that are similar or better than those
and that I can use on the Surface Studio ? This is the main factor for me to buy the device. Thanks
I don't know about Zen Brush 2, but it seems quite popular among Chinese Calligraphers - Apple certainly did a great job making their products appealing to Chinese users.
I have a history of practicing calligraphy on Windows. On Windows, to simulate a high quality oriental calligraphy brush you'll have to rely on professional painting programs such as Photoshop or Clip Studio Paint. The apps in the store are not up to the
task, unfortunately, or I would have recommended Sketchable.
Here is an example I could achieve with Clip Studio Paint on my Surface Studio - the left is the original template, the right is my calligraphy copy of the left. You can see my customized brush is still far from perfect, missing fine features here and there,
but the feel of the brush is as close as I can get compared to a real calligraphy brush. And yes, I can reproduce the calligraphy fairly quickly and easily. I think for practice purpose, there is not a single problem. I can make a tutorial video if people
are interested.

The Clip Studio Paint is free for trial for unlimited times. The only function limitation is that it cannot save your work - but you can always do a screenshot if you want to export your work. For calligraphy practice, it's my day to day go to program (and
it's really a free program in the sense that I am only practicing and not saving anything). Of course, for real production you'll eventually have to rely on a real brush and real paper. But practicing on computer for training purpose is invaluable.
My other issue with digital calligraphy on computer is that the stylus (Surface Pen) is too short compared to a real brush - so you can only comfortably hold it like a pen instead of a brush (in terms of hand positioning if you know what I am talking about).
This does not help you learn real calligraphy much given the real brush is very long. The Apple pencil is much longer than the Surface Pen and more akin to a brush IMO and should help learn hand positioning better. Anyway, I prefer to use the Surface Pen as
a pen for my calligraphy training but in real calligraphy the brush is always used upright. It does not prevent you from using the Surface Pen upright however, and you can indeed, use the Surface Pen upright to practice calligraphy - but it simply feels awkward
to use given its short length.
Please don't take my comment as your shopping guide. I have absolutely no knowledge of how well Zen Brush approximates to a real brush. But after seeing a few YouTube videos of calligraphy on Zen Brush (with Apple pencil of course), I cannot say that I am
very impressed.