Yupo is a synthetic substrate that artists have been using alcohol ink on for several years now, and as it is plastic, some bright spark worked out that you could burn it with a soldering iron or wood burning tool. These are my samples. All of the layers are created using 2-3mm foam squares to create the dimension. To call this a fiddly process, would be the understatement of the year!
A word of caution.... heating/melting/burning plastic is toxic and should always be done outdoors in moderation. This is not something I plan on doing every single day so a respirator is unnecessary. If you were considering doing this technique more frequently, look after your health and use a respirator. I have burnt the holes/shapes beforehand and then inked on some, but have also done the burning when the Yupo was already inked and dry. The final one, Traverse, is slightly different but the top of the hills are still burnt/melted with the soldering iron to create the shape. You don't want to cover these up too much, hence the need for minimal decorating.
"Firecracker"...
"Elemental"..
"Nocturnal"...
"Mushroom"...
"Traverse"...