Jumbo cupcake liner

This project was a pain, mostly because the silicone does not want to release from a closed mold. I tried a couple things, but splitting the mold was the only way to separate the two halves. The downside was an ugly seam..
Printed parts were just not strong enough to pry apart with a screwdriver. I tried wetting it and microwaving, for a hot steam expansion effect. Nothing I tried worked.

While messing around with some new TPU filament, I got the idea for a flexible mold that can stretch a little bit. I used PETG for the inner part and TPU for the outside. This worked.

The fit at the seam is pretty tight, but I still ran a bead of sulfur-free modeling clay around the seam to prevent any leaks. (There were no leaks under that clay) Also spread a little petroleum jelly on the mold surfaces for sealing, and for hopefully easier release.

When cured, very carefully pry the seam apart. Once a small spot starts to loosen and air gets in there, the whole thing releases.

I used 0.3mm la