r/DiceMaking • u/looppii • 7d ago

Why do my dice have fingerprint-like marks after demolding? I’m sure the master dice were completely clean when I made the mold.

When I demold my dice, I notice fingerprint-like marks on the non-top surface (the side that doesn’t touch the cap), especially on the upper part of the dice. I checked the silicone mold and found similar patterns on the mold itself.

However, when I made the mold, my master dice were clean.

Can anyone help me analyze what might be causing this issue?

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7

u/hulahoophug Dice Maker 7d ago

If it's on the mold too then at some point you transferred some oil from your fingers onto your masters. Did you wear gloves when positioning them to make the mold?

Sometimes when I make molds the transfer tape I use to stick the masters down will get stuck on the side of a die when I'm trying to stick them down. that will also cause marks from the tape to show up in the mold so it's best to wipe them thoroughly with a microfiber cloth and place them again if that happens.

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u/looppii 5d ago

I wasn’t wearing gloves when I positioned the masters to make the mold, but I don’t think it was oil or fingerprints from my hands because I only touched the upper part of the dice while placing them. The oily marks appeared on the bottom edge of the dice, where it was in contact with the transfer tape.

Could this have been caused by applying too much petroleum jelly on the mold surface and having it seep down?

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u/looppii 5d ago

You can see that the two photos are actually of two different faces of the D4, not the same face. When I placed the D4 master onto the transfer tape, I held it by the top and the tip of the die, not near the area that was touching the transfer tape.

5

u/RandoBoomer 7d ago

I had this happen too. The oil from my fingerprint transferred to my masters while I was placing them.

Now I use rubber-tipped tweezers.

0

u/looppii 5d ago

I wasn’t wearing gloves when I positioned the masters to make the mold, but I don’t think it was oil or fingerprints from my hands because I only touched the upper part of the dice while placing them. The oily marks appeared on the bottom edge of the dice, where it was in contact with the transfer tape.

Could this have been caused by applying too much petroleum jelly on the mold surface and having it seep down?

1

u/RandoBoomer 5d ago

Fingerprints on the tape could transfer if they touch a die surface. Clear transfer tape is used in police capturing of fingerprints.

Purely speculation, but I would think the petroleum jelly wouldn't give you the precision of a fingerprint and instead give you a "blob". I haven't experienced this first-hand, so I defer to anyone who has.

1

u/Repulsive-Hedgehog27 6d ago

I use gloves to handle my masters once it's time to make a mold. I will give a quick polish and then place on the tape while wearing gloves. You can trasnfer oils just buy holding the masters with your fingers.