Hi all,
I’m researching windows apps/software that can be used as digital platforms for that recent craze - Coloring in for adults! Do you use MyPaint to color in line-art? What’s your workflow? Is it easy to use? What problems do you encounter?
Have fun making art!
Cheers,
Susan
(A polite request: please let everyone know what your affiliation is, if it’s a formal research project. Thanks! 
)
Sounds like a good topic for discussion. Maybe there are Libre Graphics resources for people wanting to do this? A quick search on OpenClipArt and Wikimedia Commons uncovers quite a few "mandala"s and “coloring” resources.
There’s a wealth of out-of-copyright line art being digitized too: take the British Library’s archives, for example. There’s all sorts of book illustrations and designs there, hopefully tagged now.
I guess the goal wouldn’t be to use something as mechanical as the bucket fill tool on linework for this sort of contemplative/meditative pastime! You’d paint within the lines somehow, perhaps in a new layer on top in Multiply mode, if the image you’re colouring in has a white background.
If your goal is tinting old public domain photographs - things already in greyscale - then MyPaint has a very nifty Colourise brush blend mode that I’d encourage you to try out. This one you use directly on the target layer.
It won’t work on pure black/pure white images like the one above though; just stuff with grey shades between the extremes.
And just in case anyone’s wondering what this is all about:
Nah this is nothing official I’m just ‘researching’ of my own accord. 
My first impressions of MyPaint are really good. The layers make it easy to control my line art and ‘protect’ it from my dummy colouring hand. Starting a new layer for a new colour is a good idea until I’m happy with it too
I believe that colouring has been a thing in Anime fan art for some time as well. I’m sure artists like this are around and using MyPaint.
Now just to organise a ‘marketplace’ of sorts for line-art
Thanks!
