An undesired adhesion between touching layers of material caused by moderate pressure and/or temperature change. The extent to which damage to at least one surface is visible upon their separation.



- Ink not drying on substrate;

- Ink skinned - Trapping solvent;

- Web rewound too warm;

- Excessive rewind pressure;

- Film treated on both sides, especially if treatment is different between each side;

- Plasticisers in film subjects to migration e.g. some vinyl films;

- Surface moisture on web;

- Excessive weight in stack;

- Pre-applied coating softens.



- Adjust solvent balance, use faster solvents. Check dryers;

- Use less heat initially. Reduce viscosity which reduces film thickness. Check dryers;

- Reduce web temperature by chilling to within 5°C of ambient. Instant chill rollers or reduce dryer temperature;

- Reduce web tension;

- Avoid excess pressure on re-reeling, use a non blocking varnish over inks. Best solution is to ensure film specification is correct at start;

- Avoid excess pressure, use non blocking overprint varnish. Use inks with non migratory pigments;

- Avoid over chilling especially in humid conditions where moisture condenses on cooled web;

- Reduce stack height;

- Change to solvents that do not attack prior coatings.