Scratch-off Ticket & Card Ink

What are scratch card and ticket security inks

Scratch card and ticket security inks are printing inks for scratch cards, lottery tickets, raffle tickets, recharge card PIN layers and admission tickets. They fall into two parts: a scratch-off layer ink (scratch silver / scratch colour) that conceals the underlying information, and a security ink (UV invisible, thermochromic, IR excitation) that makes the ticket itself hard to forge. The first keeps the information hidden until scratched; the second stops the ticket being casually copied.

Shenzhen Sojhonink Co., Ltd. was founded in 2002 and produces nearly 1,000 tons of ink a year. We have supplied inks to card, ticket and security printers as a long-term partner, working across screen, offset and flexo, adjusting formulation to the substrate, post-press and secrecy requirements, and providing free printed proofs for colour selection and press trials.

The three tensions in a scratch-off layer: full coverage, smooth scratching, opacity

The scratch-off layer looks simple but is really a set of conflicting requirements that must hold at once:

Full coverage — the layer must completely hide the underlying information from any angle, with no pinholes, show-through or faint reveal.
Smooth scratching — the consumer should scratch it off smoothly, in clean flakes, leaving no residue and revealing the information intact.
Opacity — even under strong backlight the layer must not let the underlying digits or pattern show through. This is the bottom line for secrecy.

These pull against each other: stronger coverage usually means a thicker film and harder scratching, while a light, easy scratch can cost coverage. The final balance depends on the scratch-off ink formulation, film thickness, primer and drying conditions, and has to be confirmed item by item through a proof.

Silver and coloured scratch inks, and customising the scratch feel

Both the appearance and the feel of the scratch-off layer can be tailored:

Dimension	Options	Notes
Appearance	Silver, gold, black, colour	Silver-grey is the common general look; gold and colour usually follow brand visuals
System	Water-based, oil-based	Water-based is more eco-friendly and low-odour; oil-based can hold coverage and feel better on some substrates — choose by substrate
Scratch feel	Easy, medium, harder	Adjusted by formulation; with the primer this delivers “clean flake-off” or “gradual removal”
Secrecy	Standard, reinforced	Reinforced grades target backlight inspection, reducing show-through

Because “scratch feel” depends heavily on the interplay between the primer and the substrate, we recommend settling it together with the primer information by proof, rather than specifying a single ink parameter in isolation.

Primer matching and common failure causes

The scratch-off layer does not work alone — it forms a system with the primer and substrate. The three most common issues in production and their causes:

Symptom	Common cause	Direction
Won’t scratch clean, leaves residue	Too much adhesion between scratch layer and primer, or high primer surface energy	Adjust primer system or scratch layer formulation so release occurs at the intended interface
Solvent attack, underlying print mottles	Solvent in the scratch layer dissolves the underlying ink or coating	Use a system compatible with the base (match water/oil systems); run a compatibility test first
Hard to scratch after storage	Film ageing from post-curing or ambient temperature and humidity	Assess scratch feel after long storage and adjust the formulation for stability if needed

These are hard to solve by swapping a single ink. It is far more effective to validate primer, scratch layer and substrate as one system at the proof stage. Further reading: common scratch-off ink printing problems and solutions and the scratch-off ink selection guide.

Multi-layer security combinations for tickets and vouchers

Tickets, raffle tickets and recharge cards are built around one-time redemption, so the security focus is preventing whole-batch forgery and reuse. A scratch layer alone is not enough; a multi-layer combination is usual:

Scratch-off layer — conceals the PIN or prize information; the base structure of any ticket.
Covert UV — a UV fluorescent mark on the ticket face, verified quickly with a 365 nm lamp at the gate without disturbing the design.
Thermochromic ink — for “body-heat” verification at the gate, or as an interactive element for child or discount tickets.
Variable QR / barcode — for item-level redemption and traceability; the ink mark acts as a second line of defence against a copied code.

The three most-used inks here are scratch-off ink, UV invisible ink and thermochromic ink, paired with card signature ink where a signature or stamp must be verified.

Choosing the scratch layer and security set by ticket type

Different ticket types make very different demands on the scratch layer and the verification method. The mapping below reflects what we commonly see on ticket projects and can serve as a starting point:

Ticket type	Scratch layer demand	Recommended combination	Verification scene
Scratch-and-win / raffle	Full coverage, smooth scratch; the prize desk must read it fast	Scratch layer + covert UV	Prize desk verifies the whole ticket with a UV lamp
Recharge / PIN card	Highest secrecy; no show-through	Scratch layer (reinforced) + covert UV	Carrier back-end redemption; channel spot checks
Admission ticket	Scratch layer mostly on the stub or verification code	Covert UV + thermochromic + variable code	Fast gate verification; thermochromic for interactive ID
Coupon / voucher	Conceals the discount code; must resist reuse	Scratch layer + variable QR	Store scans to redeem; the ink mark guards against a copied code

PIN-type cards carry the highest secrecy requirement — if the underlying digits show through or are scratched early, the loss is immediate — so these should use a reinforced-secrecy scratch layer and a dedicated backlight test at proof. Admission tickets, by contrast, care more about gate throughput and interaction, where a thermochromic plus covert UV combination fits better.

Press parameters and process notes

The scratch-off layer is mainly screen printed, with some offset or flexo. The parameters to settle on press, and what drives them:

Parameter	Main driver	How it is set
Mesh count	Required film thickness, coverage demand, pattern fineness	Confirm by proof (higher mesh = thinner film, lower coverage)
Squeegee hardness	Ink lay uniformity and edge sharpness	Confirm by proof
Dilution ratio	Ink viscosity, printability, coverage	Confirm by proof; avoid over-dilution that weakens coverage
Drying conditions	Water- vs oil-based system, substrate heat tolerance	Confirm by proof
Reference usage	Film thickness, pattern coverage	Calculated from the actual plate area and film requirement

Note: coverage, secrecy and scratch feel are very sensitive to film thickness, which in turn is set by mesh count and dilution together. These parameters should not be specified in isolation — confirm them all at once by proof once the primer and substrate are known, before volume production.

Sourcing, proofs and compliance

Packaging — 1 kg cans and 5 kg drums; minimum order quantity is flexible and can be discussed per project.
Proofs — printed proofs are provided free of charge to confirm coverage, scratch feel, colour development and general appearance. Ink samples are priced by weight.
Quotation — prices cover the ink itself only and exclude freight and taxes. Delivery is to a customer-designated location within mainland China.
Compliance — can be supplied against standards including EN71.3 and REACH. Compliance documents required for a specific project can be provided on request.
What we need before proofing — substrate type (card board / self-adhesive / film), form of the underlying information (digits / QR / pattern), primer information, printing process and press, and post-press steps.

Scratch-card and ticket projects vary widely in scratch feel and secrecy requirements. Send your substrate and primer details through Contact and we will propose a matching scratch layer and security ink set and arrange proofing.

Frequently Asked Questions

Selection, detection, printing and ordering — answered.

Why does a scratch layer show through, revealing the underlying information?

Show-through usually has three causes: insufficient film thickness, low-coverage ink, or too much contrast in the underlying information. Solutions are to increase film thickness (adjust mesh count and dilution), choose a higher-coverage system, or work with the primer to reduce show-through. For resistance to backlight inspection, use a reinforced-secrecy grade and confirm by proof.

Why won't the scratch layer scratch clean, leaving residue?

In most cases the adhesion between scratch layer and primer is too strong, so release does not occur at the intended interface. Adjust the primer or scratch layer formulation so release happens at the right point; high primer surface energy can also be a factor. Validate primer, scratch layer and substrate as one system at the proof stage.

How do I choose between water-based and oil-based scratch ink?

Water-based systems are more eco-friendly and low-odour, suiting projects with strict odour and environmental requirements. Oil-based systems can be more stable in coverage and feel on certain substrates. The key is matching the substrate and primer and the specific coverage, feel and drying requirements — determined by trial per project.

Does scratch-off ink get harder to scratch after storage?

It can. Post-curing or changes in ambient temperature and humidity age the film and alter the scratch feel. Where long storage is expected, assess scratch feel after storage at the proof stage and, if needed, adjust the formulation for stability — rather than changing it after volume production.

Beyond the scratch layer, what other security should be added to a ticket?

Tickets are built around one-time redemption, so a multi-layer combination is recommended: the scratch layer conceals the PIN or prize; UV fluorescent ink provides a covert mark for fast gate verification; thermochromic ink supports body-heat verification or interactive identification; and a variable QR code delivers item-level redemption and traceability. The ink mark is also a second defence against a copied code.

Can you give the press parameters (mesh count, squeegee, dilution) directly?

We would not specify them in isolation. Coverage, secrecy and scratch feel are highly sensitive to film thickness, which is set by mesh count and dilution together — these parameters constrain each other. We recommend confirming them all at once by proof once the primer and substrate are known, before volume production.

Still deciding? See the full 12-ink selection comparison table →