Assay Card Bar (Blister)
Also: Blister bar, Assay card, Certified bar
A precious-metal bar sealed firmly inside a tamper-evident plastic holder (blister) that carries a printed certificate of authenticity from the refinery.
An assay card bar in a blister combines a physical precious-metal bar with a certificate of authenticity that is either printed directly on the card or enclosed, permanently fixed within a sealed transparent plastic display pack (blister). The seal is built so that any opening becomes irreversibly visible - a broken blister is treated as a loss of trust and considerably reduces the dealer value. Buyers thus get an at-a-glance guarantee of fineness, weight, serial number and refinery, without having to handle the piece itself.
Structure and features
A typical blister bar consists of three layers:
- Bar - usually a minted fine-gold bar (999.9 per mille) or fine-silver bar (999 per mille) in a small to medium denomination.
- Carrier / certificate card - sturdy cardboard or aluminium bearing details of weight, fineness, serial number and the logo of the refinery.
- Blister film - a transparent, heat-sealed or ultrasonically welded plastic layer that fixes the bar to the card.
Leading refineries such as PAMP Suisse, Valcambi, Heraeus or Argor-Heraeus additionally print a hologram or a QR code on the card for digital verification.
Typical denominations
| Weight | Metal | Fineness |
|---|---|---|
| 1 g | Gold | 999.9 per mille |
| 5 g | Gold | 999.9 per mille |
| 10 g | Gold | 999.9 per mille |
| 1 g | Silver | 999 per mille |
| 10 g | Platinum | 999.5 per mille |
Small denominations suit gifts, savings plans and beginners - the gold calculator shows the current metal value per gram.
Premium and liquidity
Assay card bars cost a higher premium (agio) than comparable loose bars, owing to the packaging, certification and handling. On resale the rule is: intact blister = full dealer buy-back price; opened blister = melt-value basis minus a deduction. The current melt value is worked out by the melt value calculator. For denominations up to 100 g the premium is typically far higher than on kilo bars - that is the price of counterfeit protection and easy storage.
Counterfeit protection and testing
The sealed unit makes tampering such as drilling out or swapping in a tungsten core considerably harder. Even so, experts recommend additional methods when in doubt: weight check, Archimedes density measurement or X-ray fluorescence analysis (XRF). The authenticity checker supplies reference values for weight and dimensions.
Note: tax treatment (VAT, holding period) depends on the metal, the holding duration and individual circumstances. In Ireland, investment gold is VAT-exempt, while silver, platinum and palladium carry the standard VAT rate of 23 %; a gain on disposal may be liable to Capital Gains Tax at 33 %. This is not tax advice.
In short
Assay card bars in a blister combine physical security with documented authenticity and are especially suited to small weight classes and safe onward transfer - as long as the seal stays intact, the resale value is easy to verify.