Troubleshooting

Printing troubleshooting guides

69 guides to common faults, grouped by the technology you run — offset, flexo, gravure, digital, screen, label, large format and finishing. Written to stay true, not to chase a date.

Offset7

What causes hickies (donut-shaped spots) on my offset print and how do I get rid of them?Why does my color keep drifting during an offset run — density and dot gain shift from start to finish?Why does my offset print show ghosting — a faint repeat or shadow of an image inside solid areas?Why is ink setting off — the back of my printed sheets is picking up ink from the sheet below in the delivery pile?Why is material piling up on my offset blanket — ink or paper coating building up so print quality drops during the run?Why is my offset press scumming — ink showing up in the non-image (blank) areas of the sheet?Why won't my colors register — the color-to-color or front-to-back registration keeps drifting off on the offset press?

Gravure7

Cells are plugging with dried ink — missing dots and weak, patchy print in the same spots Colors won't stay in register station-to-station (register drift / web tension problems)Getting fine lines or streaks running in the web direction (doctor blade lines / chatter)Heavy solids look mottled with tiny white pinholes (snowflaking / poor ink transfer)Printed film smells of solvent or fails residual-solvent limits (retained solvent / odor)Random unprinted specks, pinholes, and ringed spots scattered in the print (skips / hickies)The cylinder is getting scored and blades wear out fast — a permanent line in the print

Screen6

Why are my screens losing tension and prints coming out blurry or shifting?Why do my colors keep drifting out of registration on multi-color jobs?Why does my ink keep drying in the mesh and clogging the screen during long runs?Why does my stencil have pinholes and start breaking down partway through a run?Why is my plastisol print bleeding or changing color on polyester garments?Why is there a ghost image or haze left in my mesh after I reclaim the screen?

Finishing & Post-Press6

My cutting table is leaving ragged, frayed, or incomplete cuts — is it the blade?My cutting table's registration camera can't find or misreads the print marks My die-cut lines don't line up with the printed image — how do I fix registration drift?My foil or spot UV is peeling or won't stick — how do I fix the adhesion?My folding cartons are cracking on the outside of the fold at the crease — how do I stop it?My laminate is bubbling or peeling off the print — how do I get proper adhesion?

Digital Toner7

A faint second copy of the image appears further down the page (offset/ghosting) — why?Colors are misregistered or front-to-back alignment drifts during a run — how do I correct it?Sheets come out curled or full of static and keep jamming after the fuser — how do I stop it?The same spot or mark repeats at a regular interval down every page — how do I find which part is failing?Toner scratches, flakes, or rubs off my coated or synthetic stock — how do I fix adhesion?Vertical streaks or white lines run down the length of my prints — what's causing them?Why do I see horizontal light-and-dark bands (banding) running across my prints?

Digital Inkjet7

Colors are out of register or the back doesn't line up with the front — how do I fix inkjet misregistration?Prints come out tacky, set off in the stack, or crack when folded — how do I fix drying/curing?Repeating light and dark bands across my inkjet output — what causes banding and how do I fix it?Sheets are double-feeding, jamming, or clinging from static — how do I fix inkjet feed and media-handling problems?Text and edges look fuzzy and colors mottle on uncoated paper — how do I stop ink bleed and feathering?The printhead is smearing ink or scraping the paper — how do I prevent and recover from a head strike/crash?Thin white lines running in the print direction — how do I clear clogged or missing nozzles?

Label Printing - Inkjet6

Why are my film labels sticking together, mis-feeding, or clinging to the press from static?Why does my die-cut drift out of register with the printed image partway through the run?Why does my label web wrinkle and wander off track through the press?Why does my waste matrix keep breaking or labels lift with the matrix during inline die-cutting?Why does the ink rub off or fail adhesion on my filmic/synthetic label stock?Why is adhesive oozing out of my die-cut label edges and gumming up the press?

Label Printing - Toner5

My labels come off the roll wrinkled and the print keeps wandering across the web — how do I fix web tension and tracking?My printed labels are sticking together and misfeeding off the roll — is this a static problem?The color shifts from the start to the end of a long roll run — how do I keep color consistent across the whole roll?The fuser is curling my labels and squeezing out adhesive — why does my label stock distort or jam in the fuser?Why does the toner scratch or flake off my film/synthetic label stock?

Flexo7

Color is coming out weak and washed-out even with plenty of ink - is my anilox plugged?Faint repeated 'ghost' images are showing up in my solid areas - how do I stop ghosting?I'm getting evenly-spaced light-and-dark bars across the web - what's causing this banding?My colors won't stay in register - how do I fix misregistration on the flexo press?My ink keeps skinning and drying on the plate and anilox during the run - how do I control drying?My solid ink areas have tiny unprinted specks (pinholes) - how do I get full coverage?Why are my highlight dots plugging up and filling in on press?

CTP / Prepress5

Dots on my imaged plate don't match the file — highlights dropping out or shadows plugging (dot gain/loss)Image is imaged in the wrong position / my plates won't register on press (punch and clamp alignment)My CTP plates keep getting scratched or scuffed during imaging and handling Plates come out scummy or with a weak, blinding image — is it my processor chemistry?Straight lines, streaks, or banding across the plate, or faint/missing dots in patches

Large Format6

Colors don't match between panels of a tiled job or between reprints, how do I get consistent color?Missing nozzles and streaking after the printer sat idle overnight or over the weekend, how do I recover the jets?My banner or vinyl skews and wanders to one side during long roll-to-roll runs, how do I fix the media feed?The ink scratches off, smears, or won't stay cured on vinyl, film, textile, or rigid board, how do I get proper adhesion?The printhead is hitting or scraping the board on my UV flatbed and leaving streaks and scratches, how do I stop head strikes?Why do I get horizontal banding or streaks across large solid color areas on my wide format prints?