This was a really tough one, and a huge learning experience. For those who don't know, Slushh is a green, humanoid blob of acid that has bits of previous victims and parts of his Sinestro Corps uniform suspended in him.
I was asked to do this custom, and I was warned that it was a huge challenge and others had said it was impossible. I love a challenge!
I'm not sure how successful I was though.
I used a Japanese transparent clay called Toumei Nendo (translated as the cleverly named Transparent Clay. lol). That degree in Japanese came in useful in researching this stuff. It's very difficult to use, and to be honest, I cannot recommend it for customs as it is primarily designed for bead making and doesn't hold a sculpt well at all. It's very rubbery and takes days to cure, and then it just shrugs off paint. Urgh.
Anyway, I made a skeleton for Slushh from parts of a dinosaur skeleton toy, and made parts of the Sinestro Corps uniform from my usual paper mache. I assembled the skeleton with hot glue and articulated it with joints from a transparent Super Skrull and Judge Death.
I then covered it with the Transparent Clay. I made sure to only touch the clay through a freezer bag, so that it wouldn't pick up any dirt or debris from my customiser's paws. As the clay dried it lost a lot of its transparency, becoming cloudy, and much of the work I put into the skeleton and the details inside him became really tough to see.
After leaving it for about a week, it was ready to paint (or so I thought). This sucker just wouldn't take ANY paint at all. In the end I had to mix Tamiya clear green with PVA glue and gloss varnish to get this thing to take any kind of colour. It wasn't a smooth finish like I aimed for so I did my best to dry brush it and clean it up.
Anyway, here he is. I'm pretty happy with the whole experience and it was really neat to get a big challenge like this.