Scratch-off ink is the core material for instant lottery, promotional and security cards. Common faults: too hard to scratch, bleed-through, powdering and residue. Here are the causes and fixes.
1. Too Hard to Scratch
Over-thick covering layer, hard formula or over-drying. Fix: print 2-3 thin even coats, match formula hardness to the scratching tool, control drying temperature.
2. Bleed-through (Poor Coverage)
Underlying graphics visible before scratching. Fix: more printing passes, high-coverage ink (opaque, non-transparent from the back), even printing without voids.
3. Powdering / Peeling
Coating falls off during transport or before scratching. Fix: high-adhesion formula, proper substrate treatment, better abrasion resistance.
4. Residue After Scratching
Leftover ink marks. Fix: optimize film former ratio so the coating peels off cleanly in one scratch.
SJH Ink Advantages
- Strong coverage, opaque, non-transparent from the back
- Excellent tamper-evident secrecy
- Abrasion resistant
- Clean scratch, no residue
- Water/oil based; scratch gold, silver, black
Shenzhen SJH Ink Co., Ltd. (est. 2002, 14 Fuxing Road, Pinghu, Longgang District, Shenzhen) offers free samples. Tel 13510998453, www.sjhink.com.