These supports are for "standard" size dice. The dice masters I used were purchased from The Blue Mimic in a standard size. You can edit the sizes of the supports if they aren't the right sizes for your dice, but they should be fairly close for most standard size dice. The "D20 L" file was made to be used with a 23mm D20. The silicone I use for molds is Mold Star 20T from Smooth-On, but you can use anything you feel comfortable with that will cure against 3D printed parts.

These dice mold supports are for two-part "squish" style mold making with added vents. The bases are sized so that there is adequate space between dice if you are placing them all together in a mold.

I will provide photos to make it easier to understand the instructions at a later date.

I suggest drilling a sprue/vent support hole in the single face of the dice you want to use for the "rough" side. It should be the only side that you need to sand and polish after removing the dice from the molds. The supports have a slight indentation to them that will make the mold caps "pop" into place when putting them into the bottom molds. I suggest filling them using the sprue/vent hole, since it is the least messy, but you can also fill them and then place the cap on, which is helpful for making intricate designs or using inclusions.

I use double-sided tape to affix the dice to the top of the support, but you can also use very thin clay, but that will require a little more cleanup in the cap making phase. When you use the tape, you have to remove the supports from the mold more carefully so you don't move the dice master before casting the cap. You also have to cut the tape carefully when applying it to the support. I use an Exacto knife to cut around it after placing the tape firmly down.

I drill a hole in the "rough" face of the dice. Usually I use the smallest number face, so that if I do any designs with inclusions, the largest/most important face looks the best. The hole should be less than 2mm. Once you remove the support and before you cast the mold cap, you can attach the 3D printed sprue/vent to the dice using clay or bluetack. The sprues/vents are optional, however, so you can skip that part if you'd rather cut vents yourself or make molds without vents.

You have to apply a mold release agent after you have removed the mold support and before you pour the silicone cap, otherwise, you won't be able to separate the silicone layers from each other. I use "Mann Mold Release 200" but I have heard you can also use petroleum jelly.

If you want to edit the files yourself, I have them uploaded to TinkerCAD (You may need an account to access): https://www.tinkercad.com/things/gCJiz7fdn32-dice-mold-supports-shared