yes, otherwise it will stick. the paper will peel. it has been so long since i've had a chance to do it but i believe i ended up switching to foam core because it peels off easier. try some kind of spray silicone...

you could wax the chipboard on the inside, and then it will not stick.
or a more sloppy solution is putting plastic inside.. forget that.. it will be really sloppy.. stick to the wax.

i'd recommend the foamcore as well. if you want it to be really smooth and shiny nice, i'd line the formwork with mylar.

dont use chipboard--use wood

the natural grain looks cool or you could wax it

you could use PAM also but i think it would degrade the chipboard, ha ha ha

Unfortunately its too late to use anything but chipboard...ive already built the mold and its very complex. I hope the wax works---what kind of wax? I mean does it come in a lotion-like consistensy?

melt the wax, pour into mold, spread quickly.

murphy's oil soap also works well, just apply it with a paintbrush.

she don't use jelly.
she uses....

...vaseline!

Wax would be a mess, I have used lotion before or I suppose Vaseline would also work. Oil would just soak itself into the chipboard causing your form work to warp and collapse.

Thanks everyone

Ive called around and I think the best solution is a sealant + release agent, probably wax or vaseline