Pigment the RTV Tool, Not Your Food Dump | RUUIPON

Pigment in mold rubber is a shop visibility choice: a tinted platinum skin shows mix streaks, key damage, and whether you closed the two-part on the right register. It is not how you color gummies or couverture. Food color belongs in the dump kettle, with a documented path. A dye that bleeds from a cheap tray into chocolate is a different failure (migration), and we would not spec that path. For the *tool*, we use a platinum-compatible paste at a low loading so Shore and cure stay in band. Too much pigment is filler: it can inhibit, raise viscosity, and print a dusty face. Food cavities stay dry — no grease, no tin.

RUUIPON tints production RTV when the PO asks, Bao'an since 2018. Prototype 3–7 business days after CAD lock. MOQ 20 pieces per design. USD $50 when CAD scope applies. [email protected] · +86 135 3006 2969. Finished colored *parts* (HCR mill pigment, LSR color) are a different quote at wydsilicone.com.

Does not apply when you want a translucent chocolate mold so you can watch temper fill — that's a clear-grade conversation, not a pigment loading. It also does not apply to painting acrylic on a cured well "to make it pretty," or to coloring CBD/THC gummies (tooling only; we don't dose). Don't treat a tinted tray as an FDA-approved-factory claim.

Why we tint the skin, not the dump

Operators miss streaks in unpigmented 1:1 platinum under shop LEDs. A mid-grey or a named shop color makes marbling obvious before the pour hits the master. Keys on a two-part read faster when A is one tint and B another — you see a mismatch at close, not after flash. Library shelves read faster when food trays are one color family and resin tools another. That cabinet split is the point.

What pigment will not do:

• It will not make tin leftover smell like platinum.
• It will not add tear strength. Loading past the TDS is how you get a chalky, weak face.
• It will not replace a food-contact extraction. 21 CFR 177.2600 is on the finished article, including any colorant in that article. If the *dump* is food, the dump's colorant is the buyer's formula IP. If the *tool* is tinted, we name a platinum-compatible paste and keep loading low.

Migration the other way — color leaving the cavity into chocolate — is a bleed/extraction problem. We would not hide bleed with more oil in the well. Recast in a named platinum, low pigment, wash before first food dump.

Loading, streaks, and inhibition

Add pigment to Part A (or the named side on the TDS), mix until uniform, then combine A/B by weight, then vacuum. Streaks you can still see after A/B mix are off-ratio risk. A 20 g slug on a white card is the check: no marble, no dry pigment specks.

Some artist pastes and some sulfur-adjacent "rubber color" kits inhibit platinum. Confirm with a 20 g inhibitor slug against the paste before you commit a food master. If the slug stays tacky, scrap that colorant, not the CAD.

Clear tools for UV resin or for watching a fill are a different RFQ (yellowing, window storage). Don't pigment those "a little" and expect optical clarity.

flowchart TD
  A[Need color somewhere] --> B{Coloring the dump or the tool?}
  B -->|dump food| C[Buyer's formula; cavity stays platinum, dry, ungreased]
  B -->|dump craft resin| D[Color the resin; tool tint optional]
  B -->|tool visibility| E[Platinum-compatible paste, low loading]
  E --> F[20 g card + inhibitor slug]
  F -->|tacky slug| G[Reject that paste]
  F -->|cures dry| H[Tint A, mix A/B by weight, vacuum, pour]
  C --> I[177.2600 / LFGB on the article]

The photo that would prove loading: a white-card slug with uniform tint next to a marbled off-mix slug, plus the empty cavity under raking light showing no dusty transfer. A beauty shot of a red gummy is the wrong photo.

Typical shop values

Caption: Typical shop values.

Worked example (anonymized)

A 24-cavity gummy sheet plus a resin coaster from the same logo art. Buyer asked to "dye the silicone red so the gummies come out red." We split the PO: food sheet in untinted or lightly grey platinum, dump color in their kettle, 177.2600 path named; resin coaster tool tinted green so the craft cabinet cannot be grabbed by the food line. $50 CAD once, shared master, two skins. MOQ 20 per design. The red gummy color never went through the well.

One procurement mix-up

"Food-safe colorant" on a craft-store bottle is not permission to pigment a chocolate cavity, and it is not 177.2600. Buyers also send a Pantone for the *gummy* and expect us to match it in the rubber. Rubber tint is a shop aid. Dump color is formula. Tooling charge is not ownership of their flavor IP.

We would not recommend

We would not recommend coloring chocolate or gummies by bleeding dye out of the mold.

We would not recommend oiling a food well to "set" a pigment.

We would not recommend artist oil paints as platinum colorant.

We would not recommend one tinted skin shared across food and resin cabinets.

What to ask when you're buying

• Is the tint for operator visibility, cabinet split, or a clear-watch fill (don't pigment that)?
• Named platinum-compatible paste, and do we run an inhibitor slug?
• Food docs on the article, including any tool tint?
• Same master, two skins, if food and craft both ship?
• Who owns the master at reorder?

RFQ copy-pack

Send to [email protected] · +86 135 3006 2969 · Xinhe Blvd, Shajing, Bao'an.

RUUIPON mold-rubber pigment RFQ Dump: food / craft resin / plaster / other Tool tint: none / shop grey / two-tone keys / other named Clear-watch fill needed? yes (no pigment) / no Inhibitor slug on the paste? yes Food docs: 177.2600 / LFGB / none Qty: witness / MOQ 20 per design CAD: locked / $50 3D if art still open

Matched next step: say whether tint is for the tool or for the dump. We color skins for visibility. We will not dye couverture through a well. Prototype 3–7 business days after CAD lock. MOQ 20 per design.

Related: food-grade silicone molds, custom resin molds, platinum vs tin for food, contact.

FAQ

Will a grey tool make grey chocolate? Not if the pigment is a low-loading platinum paste that stays in the network. Dusty transfer means the loading or the paste was wrong — recast, don't oil the well.

Can I use the same red skin for strawberry gummies and red resin dice? We would not. Cabinets split. Resin retires a well from food even if the tint matches a brand color.

Does pigment change Shore A? High loading acts as filler and can shift hardness and tear. Stay inside the TDS. Measure Shore on a thick coupon, not on a 3 mm tray lip.

Do I pay CAD again to change only the tool color on reorder? Usually no. Color is a mix note. USD $50 applies when geometry is still open. MOQ 20 still applies per design.

Is a tinted tray "FDA colored silicone"? No. There is no FDA-approved-factory stamp in that phrase. Name the article extraction and the paste family.