Been trying out some apps that turn your tablet/phone into a pen display for your PC.  Thanks to a user, I now come across SuperDisplay. To use Expresii with SuperDsiplay, please use Expresii 2020.12.29 or later. Otherwise, you need to first disable Wintab driver in the current SuperDisplay before you launch Expresii. I've been in contact with the author of SuperDisplay   and and he confirms that future version of SuperDisplay would have this fixed.

Among the similar apps that I've tried, SuperDisplay is the first one that feels a charm to use! It is very fast even on 2.4GHz wifi.   There're many options like having our Android device in extended display mode, customizable on-screen icons (can have different assignment for long press) for undo, redo and more.   Connect wired or wireless. 

The following is a comparison between using my phone as extended display  vs mirrored display at 4k. My computer (AMD 2400G APU with 16GB of RAM) is stressed when it needs to handle two 4k displays causing lag in the strokes, but if you use mirrored mode, it's quite fast:

If you only  use FHD, it should run even smoother.   

Here's a video showing how to setup custom on-screen icons in SuerDisplay and a demo of using them:

The on-screen icons may be  taking too much of your real estate.  However, the above videos are done on the Samsung Note 8 phone.  Want to see how it looks if you use a tablet?  Someone actually has already posted  a demo video of using Expresii with SuperDisplay before me:

He is using a Samsung Tab S4 , a 10.5" Android tablet (2018, Super AMOLED, 1600 x 2560 pixels, 16:10 ratio). As suggested by reviews on Google Play,  another good tablet you can use is the newer Samsung Tab S6 Lite (2020, 10.4"   TFT, 1200 x 2000 pixels, 5:3 ratio), which is sold for US$325 at Amazon. If you're  in Hong Kong, dcfever has several listings at HK$2000 only    (=USD258) right now.  So, yeah, you can pretty much have something like a   wireless Cintiq for 200 or 300 something.

SuperDisplay is current sold at USD10. Well worth the money if you ask me.  ^_^

I tried my Xiaomi Mi A1 (Snapdragon 625, 4+64GB), a budget phone released in 2017. The performance is a bit slower than my Samsung Note 8  (Snapdragon 835, 6+128GB), a flagship phone also from 2017. With more testing, I found that when doing multi-touch gesture (that requires when  fullscreen refresh) would be more laggy if I have more tabs opened in Chrome on my PC. Apparently, the most demanding task SuperDisplay does is the compression of your screen on our PC end and thus the bottomneck.

From Google Play reviews, it looks like the 2019 Samsung Tab A with S Pen works well, and  it's quite a budget device at US$245.

2021.01.09 update:  The author of SuperDisplay told me that for most cases the bottleneck is in the decoder on the Android device. And on your PC, GPU is used for the encoding, so having a fast GPU helps in getting faster response.

2020 went too quickly. No travel. In fact, our activities were mostly confined in our neighborhood.​  Nevertheless, the development of Expresii never stopped. Just check our Update Log for a (truncated) list of what have been done.  

Have been collaborating with a small team of animators this year on a short film Find Find , whose production started in March.  It serves as an experiment for how Expresii can be used for animation. We are developing a system that can automatically control the brush (and other attributes like color loading) in Expresii to produce a sequence of animation frames.  This lays a ground for modern ink-painting animation  (水墨動畫). Click the octopus below to watch an illustrative video.

The animation is set to premiere  in mid-2021.   

In mid-2020, it's been proven that Expresii can run on an Intel-based Mac via Parallels Desktop 15 or later, complete with Apple Pencil support (with pressure and tilt) via Sidecar, but the save / export function of Expresii was not working  due to limitation of Parallels' OpenGL implementation. Since version 2020.11.01, we updated Expresii to overcome this limitation so that it can now run  fully via Parallels. So, yeah, apart from running Expresii via Bootcamp, you can now run it directly from within MacOS via Parallels. 

However, it seems Apple is ditching Intel processors for future Mac's in flavor of their own ARM-based processors. For Expresii to run on ARM,  a crucial part from Microsoft is the support of  OpenGL 3.3+ for Windows on ARM. They have good progress on this, citing   in November   an   Insider version of the compatibility package  that one can test with.  Since one can already   run Windows on ARM on Apple's new M1-based machines, it's quite possible we can run Expresii on ARM-based Apple hardware. 

Those of you having an ARM-based machine can try Windows on ARM (if on Apple M1, here's an   installation guide) and get the   Insider preview     of the OpenGL 3.3 package to try Expresii there already. For those of you hoping to run it via   Parallels,  Parallels just released a   tech preview  in which you can run Windows on ARM as virtual machine  on an M1 Apple machines. So for those of you having a Parallels 16 license, you can already try it.   If you do try them, let me know how it goes!  

2021-04 Update:   Yes, Expresii  runs on Windows 10 ARM version via Parallels 16.5 on Apple Silicon M1 machine!

In March 2020, we got a call from Taiwanese company Ufro.  Their CEO would like us to support their new color-picking mechanism, in preparation for the then-upcoming Lenovo E-Color Pen. We're happy to help. In July this E-Color Pen started to hit the market, and we did some demos for it. Expresii became the only app that can show off this E-Color Pen with gorgeous  color blending effects. 

In May, we added support for on-the-fly adjustment of loading color hue, lightness & saturation via hotkeys in Expresii.   More pen tablet makers are adding dials to their hardware and we also showed you can use those dials for real-time  color adjustment  by assigning the dial to our hotkeys. 

We have been in contact with other hardware makers  too.  Would reveal more when collaborations come to fruition.

Since February, the file size of an Expresii artwork file and in-memory storage size are significantly reduced.   In October, the artwork export rendering implementation is replaced with one that is more amenable to having more layers.  In December, artwork  rendering is also optimized to up to 50% faster (or  80% for a bit lower quality). These path the way  to allowing more layers  or future enhancements. 

Sorry for the lack of a roadmap thus far.   Since the internal of Expresii is much more complex than ordinary paint programs, it takes more effort to design and implement stuffs.  Quite some users still don't have a good GPU and without  a good GPU, we have to be economical when using GPU resources. Now that hardware has improved and capable GPUs are more common in new machines, we'd like to update Expresii to allow better experience given more available GPU compute and memory   resources.

Suminagashi is a form of marbling.  In October, we   gave a preview   of our implementation in Expresii and we passed it to our trusted user Shuen Leung, and she produced the following artwork:

There is still some more work to be done before we can release it to the public. Let us know how you like it so far.

I know many of you find it hard to paint when the paint never really dries and needing to use a new layer for sharp overlapping shapes.   That would change soon. 

With those optimizations mentioned above, we're ready to add support for more layers.

We'll start adding Western watercolor specific features like drips, backruns or granulation.

Some of you were asking for image import.  With that above-mentioned dry-up change, import would be possible.

Our Nelson Chu has been thinking about how to do even better than what he did for oil paint simulation in  Fresh Paint (Project Gustav) . Hopefully, we can come up with a good solution in the coming year following Western watercolor.

We already have an initial implementation of the RYB color model. This makes the colors look more natural, but it actually narrows the range of possible colors you can get. The greys become kind of sepia. 

Existing customers will get these enhancements for free.  So, you don't need to wait if you want to purchase Expresii now.  ​ (^人^)

​If you like what we're doing, please support this endeavor by buying the app (or giving a tip by paying for a trial key) and tell your friends who might be interested.  Everything counts!     Thanks you!      m(_    _)m 

Apart from Duet Display  Pro,  there's also Easy Canvas Pro from DEVGURU Co.  in   Korea that allows you to use your iOS or Android device as pen display to your desktop apps.  Yes, it's like connecting a Cintiq to your desktop, but you have the option to go either wired or wireless.  You can use a tablet like   the iPad or  the   Samsung Tab S3   or even your Samsung Note 10 phone.  It'd be  a great solution if you already own one of those devices.

We just tested  their newly released   EasyCanvas Pro for Android . I own a Samsung Note 8 with S Pen, which supports both pressure and tilt, so I used it in this test.  Normally, you should use a tablet instead since a phone's screen is very small for painting.

I found the wired connection gives satisfactory performance. When using 2.4GHz wifi, the delay is rather noticeable.   Unfortunately, I don't have a 5GHz router here so I can't test 5GHz   performance. The Samsung device shows the 2.4GHz wifi  giving 144Mbps, while my test desktop is connected to the wireless router via cable.  My desktop screen is at 4k and my phone is set at FHD+, so Easy Canvas has to resample the 4k screen capture and that's another source of latency.   

We hope DEVGURU can support G-Sensor data and hover in the future.   G-Sensor can be used for surface tilt to direct the paint flow, and hover is good for users to see the pen posture before hitting the paper. This is important for Eastern calligraphy, if not for painting in general.