Have you ever licked a cactus? Probably not. But it might be interesting to try it out, in another form. Time to create some special sensations for our tongues! In this instructable I'll make a cactus-inspired popsicle and demonstrate the two-part silicone casting process.
Here's an instructable that introduces you to mold making basics. Making a two-part mold has versatile applications and is beginner friendly. Here I used a combination of one-part and two-part mold-making techniques.
I modeled the cactus shape in Rhino, exported as .stl file, and got it printed on an Objet 3d printer. If you don't have access to a 3d printer, you can always use online 3d printing services like Shapeways and Materialise.
As you can see the model is very symmetrical, with a clear front and back (where the spikes are). So for our two-part mold the parting line will be the center line between the front and the back. If you're working with a more complex geometry, try to mark your parting line so that it avoids delicate details. Note that the parting line doesn't need to be on a flat plane.