Painting on Glass! - Possible Practitioner

As part of my PPP I want to look at interacting with Paper Panther as my practitioner/organisation, they are really inspiring to me. Above is a video of them painting onto glass to create animation and as this isn't the most popular way to animate I feel it would be interesting to get to speak to them and ask them why they would choose this. They make really beautiful animations and I feel that this is rare for a studio these days to solely create animation that they like instead of following the most popular trend. As I love to paint with oil, I would also like to find out a little bit more about the technique.