Jim, a friend at work, came in with a broken lid to his Lava Lamp and asked if I could make a replacement. I love to use my Printrbot to make replacement parts for things, so I gave it a try. This worked for him and maybe someone else will need one someday.
I used red Maker Geeks PET+ since this might get a bit warm and PET+ is much more heat resistant than PLA. Printed with 4 top and bottom layers, 2 shells, 245C temp.
The Maker Geeks red PET+ looks like a translucent watermelon pink when printed. Not the look Jim was going for. He sanded, primed and painted the top with some rattle-can semi flat black paint. He reports no issues with heat affecting the lid so far.