SJH scratch-off ink coverage and scratch effect test: strong adhesion and full coverage, reveals text when scratched - widely used for scratch cards, lottery cards, promo cards and security coupons.
A full written description of the demonstration, so the content is readable without playing the video.
This video demonstrates the coverage and scratch behaviour of SJH scratch-off ink: strong concealment and clean reveal when scratched - for scratch cards, lottery cards and security coupons.
The video first shows the finished scratch card, where the silver or specified ink layer fully covers the prize information and QR code underneath. The hidden content cannot be read from the front, at an angle, or by backlighting. Coverage is the first specification of scratch-off ink - incomplete coverage means failed security - so opacity and non-show-through are the acceptance criteria in production.
The camera records the scratch-off process: the ink layer peels away in sheets along the scratching direction, revealing the text and pattern cleanly, without leaving debris at the edges or tearing the base sheet. The feel depends on the balance of adhesion between ink layer and substrate - too strong and it will not scratch cleanly, too weak and it flakes off during transport friction. That balance has to be established by proofing on the customer substrate (coated paper, white card, PET, etc.).
Once scratched, the underlying prize code and serial number remain intact for scanning or manual verification. This is why scratch-off ink cannot be specified on concealment and peel alone: the base print must survive the scratching. In production it is therefore supplied as a matched system of base ink plus scratch-off ink, not as a standalone ink.
| Core specs | Coverage (opaque, no show-through) balanced with scratch adhesion |
|---|---|
| System | Applied as a matched base ink + scratch-off ink system so data survives scratching |
| Substrates | Coated paper, white card, PET and others; formula set by proofing on the actual substrate |
| Typical use | Scratch cards, lottery cards, promo cards, prize coupons, PIN cards |
Scratch-off looks like a simple process, but the real difficulty is balance: coverage must be complete, scratching must be clean, and the base print must survive. These pull against each other and must be tuned by proofing on the customer substrate and base ink. For prize, lottery or PIN-card applications where money is directly involved, request a printed proof to test the scratch feel and coverage before mass production.
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