BACKING BACK TRAP MOTTLE CHALKING
INCONSISTENT COLOR REPRODUCTION CRYSTALLIZATION DOT SHARPNESS
DRYING FADED COLOR GHOSTING, GLOSS
GHOSTING MECHANICAL GLOSS GRAY AND WEAK SOLIDS
HICKIES INK / WATER BALANCE

MILEAGE

MOTTLED SOLIDS MUDDY HALFTONES PICKING / LINTING
PILING PLATE BINDING PLATE WEAR
REGISTER ROLLER STRIPPING RUBBING AND SCUFFING
SCUMMING SET - OFF / BLOCKING SLINGING
SLURRED OR DOUBLE IMAGE TINTING / TONING TRAPPING
     

Problem

Cause

Solution

BACKING
New ink fails to flow and replace ink removed by fountain roller. resulting in progressively lighter
color

Insufficient in fountain, or ink is too thixotropic. Add more ink in fountain with knife to keep it fluid.
Ink too short and buttery. Consult ink manufacturer to reformulate ink for better flow.

Problem

Cause

Solution

BACK TRAP MOTTLE
Ink is pulled from the printed surface (back trapped) on to the blanket as the sheet passes through successive printing nips, creating a mottle image.
Fast setting work and turn inks. Use a more stable, slower drying ink with a lower solvent content.
Critical inks (usually dark colors or cyan and magenta) are printed in the first and second units. Change ink sequence.
Poor layout or sequence. (Solid is overprinted in another solid or a screen tint.) Change layout and / or sequence if possible to print lighter.
Improper tack sequence. Use tack graded inks, and print the highest tack first, the lowest tack last; or use properly formulated uniform tack inks.
Ink is drying during long make readies. Clean press to shorten make ready time.
Excessive ink solvent evaporation due to fast press speed. Reduce press speed and use fresh ink.
Certain gloss coated sheets have a high potential for back trap. Try other stocks.
Press design; the greater the distance from the first to last printing until, the greater the potential for mottle. Change printing sequence if possible.
Excessive paper - to - blanket squeeze. Reset to manufacturer's specification.
Certain compressible blankets. Change to quick release conventional blankets with high solvent resistance.

Problem

Cause

Solution

CHALKING
Ink pigment does not bind to stock
Too much vehicle has penetrated stock too fast. Use overprint varnish or a sealing size to bind ink to paper.
Ink does not contain enough drier for stock involved. Consult ink manufacturer to formulate ink for stock.
Stock too acidic, causing slow drying. Consult ink manufacturer to formulate ink for stock, or change stocks.
Ink film too thin (strong). Consult ink manufacturer to adjust ink for less strength.
Fountain solution pH too low. Adjust fountain solution to higher pH.
Ink too soft, providing no hold - out. Consult ink manufacturer to reformulate ink for more hold - out.

Problem

Cause

Solution

INCONSISTENT COLOR REPRODUCTION
Proofing substrate does not match printing substrate. Paper press proofs area different brightness than printing substrate. Consult manufacturer to adjust color hue and hold out of ink to match the proof. If a change in printing substrate is possible, attempt to closely duplicate the proofing substrate.
Process color prints do not match supplied proofs.

a) Consult color separator to determine what ink hue is best or reproduction of the supplied proof.

b) Obtain a new color separation prepared for condition of press room. This may be done by providing color separator with printed samples of previousjobs which exhibit typical inks and production standards realistically reproducible.

ac) Establish standard procedures. Attempts to make the job on press lead to color variation. All phases of color separation, pre-press and press operations must be carefully coordinated.

Special, spot color does not match proof. Consult ink manufacturer.
Different Pantane Color Formula Guides. The Pentane color formula Guides are reproductions of colors and subject to variations. If exact matches are required, the printer's customer, the printer and ink manufacturer must all use the same Formula Guide.

Problem

Cause

Solution

CRYSTALLIZATION

Succeeding colors do not adhere to previously dried ink.
Initial ink film is high in hard waxes. Consult ink manufacturer to formulate succeeding inks for better lay.
Too long a delay between first and succeeding colors. Run succeeding colors as quickly as possible. If job requires imprinting later leave area blank so later colors are printed on plain paper.
Excessive spray powder used on initial colors prevents adhesion. Handwipe prints to remove excess powder.
Dry inks colors have formed a hard continuous film. Consult ink manufacturer to add solvent to succeeding inks to soften previously printed colors for better adhesion.
Initial ink film contains too much drier. Consult ink manufacturer to reformulate ink.
Too much heat generated by infra - red dryer forms a hard film. Reduce drying temperature.

Problem

Cause

Solution

DOT SHARPNESS
Printed screens and reverses are plugged, appearing muddied, and show higher values than the "prog" proof shows
Too much form roller-to-plate, plate -to-blanket, or blanket -to-blanket pressure. Check setting and correct to proper pressure.
Doubled or slurred dots. See SLURRED OR DOUBLE IMAGE.
Ink body is too long and is squashing at the point of impression. Consult ink manufacturer and have provide stiffer ink.
Ink is too water receptive. Consult ink manufacturer.
Poorly ground ink. Consult ink manufacturer and have ink reworked.
Piling. See PILLING.
Plate was not sharp enough to compensate for normal dot spread from film to plate to press. Have cameraman and plate maker cooperative in making sharper halftones, negatives, positives, and plates.
Plate poorly desensitized causing image coating between halftones to print. Desensitize or remake plate.
Insufficient dampening solution. Increase dampening solution to cover plate evenly. Check or dirty dampener cover; replace if necessary.
Ink roller train is carrying too much ink. Reduce ink and reduce water.
Blankets or rollers too soft. Recondition blankets or rollers; replace if necessary.
Blankets packed incorrectly Check packing.

Problem

Cause

Solution

DRYING
Ink film remains wet or tacky in the touch
Ink is taking on too much water. Adjust ink/ water balance; consult ink manufacturer for proper adjustment.
Ink film thickness excessive. Run less ink or consult ink manufacturer to increase strength for this purpose.
Plate dampening is uneven. Keep dampeners clean and clean from accumulated dirt. Prevent drafts, check windows, vents, and forced air system.
Stock is not porous enough or has too high water content. Switch stock to correct porosity or water content.
PH/conductivity of fountain solution is incorrect. Check pH/ conductivity and adjust to 4.0 - 4.5 pH.
Ink not formulated for the stock. Consult ink manufacturer.
Insufficient air/ oxygen circulation. Wind sheets between printing and other operation. Use anti- set- off spray to keep sheets apart. Imprevious sheets such as plastic and foil should be kept in small lifts, slip sheetfed or winded frequently.
Relative humidity is too high. Control Pressroom humidity.

Problem

Cause

Solution

FADED COLOR
Color is lost during drying or when exposed to light usually in large solids or solid tints.
Insufficient oxygen for complete drying causes oxidation of pigments, bleaching or burning them out. Consult ink manufacturer. If pigments are susceptible to oxidation, intermittently wind the sheets during the first few hours after printing.
Ink pigments are especially susceptible to fading. Where light fastness is important, consult ink manufacturer about using permanent pigments.

Problem

Cause

Solution

GHOSTING, GLOSS
(Also called CHEMICAL or GAS GHOSTING) A large solid on the back-up side of a sheet shows excessive gloss opposite the ink on the side printed first.
Large solids printed on a back - up form. Print the heavy form first, and the light form on the back up side.
Large lifts. Run small lifts when backing up the sheets.
The first side is backed-up too soon after it is rum. Hold lifts three days ( per GATF ) before printing back-up side.
Glossy sheetfeld inks. Wind sheets before printing back up side. Keep lifts in sequence for back up. Keep lifts away from sources of excessive heat or cold.Run sheets through the press without printing to supply fresh air before the back up side is printed. On small expensive runs, slip - sheet the stock while printing the second side.

Problem

Cause

Solution

GHOSTING MECHANICAL

A light to dark print of another part of the form appears in large solids of dense halftone
Poor Layout. Improve layout.
Ink film too thin. Consult ink manufacturer to weaken ink so a heavier ink film may be carried.
Ink too transparent. Consult ink manufacturer to make ink opaque, if possible.

Problem

Cause

Solution

GLOSS
(POOR) There is a decrease in the normal reflection of light from the dried ink surface
Paper too ink absorbent. Paper surface too rough and grainy has poor gloss. Consult paper manufacturer to obtain stock with more ink hold out Obtain stock with smoother surface better gloss.
Press dampeners (too much water being introduced in to inking system). Cut back on amount of fountain solution used. Consult ink manufacturer to decrease water receptivity of ink.
Ink film thickness too low. Increase ink film thickness.

Problem

Cause

Solution

GRAY AND WEAK SOLIDS

Solids appear weak, lack density

Improper ink and water balance.

Adjust to proper ink and water balance.
Improper concentration of fountain solution. Check fountain solution and adjust to proper pH/ conductivity.
Non-uniform dampening. Check condition of brushes flicker blades etc.; clean or replace.

Loss of image area.

NOTE : Additional solution to correct gray and weak solid.

See PLATE WEAR.

Check for improperly set form rollers.


Problem

Cause

Solution

HICKIES
Blemishes in the printed ink film

HICKLES WITH DARK FILLED OR OPEN GOUGHNUT SHAPED CENTERS -

Generally indicate presence of a particulate.

 
Dried ink particles. Avoid skin when removing ink from cans or kits. Protect against skin formation by placing a sheet of waxed paper on the surface. Clean the press thoroughly and prevent fresh ink from mixing with dried ink around the fountain edges. Eliminate caking on ends of rollers by regular manual washing.
Roller particles. Recondition rollers and drums. Scrub rollers with pumice water and blanket wash to remove dried ink, water soluble gum deposits and glaze. Work drums with petroleum jelly to remove surface oxidation or rust. Replace worn or disintegrating rollers as needed.
Dampener cover particles. Replace suspect sleeves or rollers as needed.
Plate particles. Check plates for loose coatings or aluminum shaving from packages. Make certain coating have been completely removed during processing.
Foreign particles. Inspect pressroom and press for cleanliness. Check heating and air conditioning systems for circulation of dust or particulates. Vacuum surface or overhead fixtures such as lights. Hang Plastic sheeting over the press to catch falling particles. Reduce application of spray power.
HICKIES WITH OPEN PINHOLE CENTERS - indicate paper may be involved.  
Loose paper coating or dust Check incoming paper. Vacuum edges before feeding in to the press. Install sheet cleaning devices.
Old, used, or tacky ink. May pull coating from paper. Consult your ink manufacturer to adjust tack and / or viscosity of ink.
Excessive dampening solution ma lift coatings from sheets. Reduce setting or dampening system. Also see INK / WATER BALANCE. Note : Properly maintained hickie - picker rollers do work. Teflon shrink wrapped rider rollers leather covered or gained rubber may be used effectively All type require frequent scrubbing for optimum performance.

Problem

Cause

Solution

INK / WATER BALANCE
Frequent adjustment required on press to maintain print quality
Excessive fountain solution. ("Orange peel effect " occurs in solid areas of print.) Reduce dampener settings. Isopropyl alcohol or an alcohol replacement can help reduce amount of fountain solution required to keep plate clean .
Fountain solution mixed too strong. (commonly seen as washed out looking color.) Ink will readily emulsify. Adjust pH to a 4.0 - 4.5 range.
Fountain solution too weak, (commonly seen in solid areas as print as " poor ink lay" or " orange peel effect ".) Increase fountain concentrate in solution to 4.0 - 4.5 range.
Improper dampening Roller setting. Reset rollers. Be sure dampener form rollers are driven by the vibrator roller and not the plate.
Improper ink form roller setting. Conduct ink stripe test to check form roller pressure.
Improper ink fountain Settings. Adjust the amount of ink at fountain. Allow adequate time for adjustment to take full effect.
Weak ink, i.e. low color strength. Consult ink manufacturer for proper adjustment.
Ink taking up too much water. Consult ink manufacturer.

Problem

Cause

Solution

MILEAGE
More ink used per impression than normal
Lack of control on color densities. Adjust color densities to minimum, consistent with satisfactory print quality.
Ink penetration into stock too rapid. Consult ink manufacturer for ink with more hold -out. Change to less porous stock.
Improper ink and water balance. Reduce amount of water carried.
Low pigmented inks. Consult ink manufacturer for proper tinctorial strength.
Excessive waste at start up of run. Improve start - up procedures.
Improper estimate of coverage from job to job. Establish ink usage history so that these figures can be used to more accurately predict ink usage.

Problem

Cause

Solution

MOTTLED SOLIDS
Printed solid area is not uniform (smooth) ink appearance or density.
Stock has non - uniform surface formation. Get better grade of paper. Consult ink manufacturer to provide weaker ink and minimize and penetrating tendencies.
Too much printing pressure. Reduce printing pressure.
Improperly set ink form roller or roller ink poor condition. Check condition and reset ink from roller to specification.
Improper ink and water balance. Adjust to paper ink and water balance.
Blanket has not been changed for a long time and has become worn and rough in certain areas. Replace with a new blanket.

Problem

Cause

Solution

MUDDY HALFTONES
Halftones lack sharpness in highlight areas.
Excessive ink being applied to the plate. Reduce ink.
Poor materials for good reproduction. Check reproduction process.
Plate improperly processed. Re - check exposure using Gray scale (Stouffer scale).
Excessive linting. See PICKING/ LINTING.
Improper form roller settings. Adjust setting to Manufacturer's specification.
Improper ink and water balance. Note : Additional solutions to correct Muddy Appearance of Halftones. Adjust to proper ink and water balance. Check for glazed blanket.

Problem

Cause

Solution

PICKING / LINTING

PICKING - Lifting of the coating from coated stocks onto blankets, plates or rollers.

LINTING - Pulling fibers uncoated stock
Too much water reaching papers. Reduce dampener setting for proper performance.
Paper surface trash, coating dust, slitter or trimmer dust. Make tape pulls from blanket, consult paper manufacturer.
Base stock picks. If serious, reject paper, change to more lint or pick - resistant stock.
Pressure set too high for ink/ stock combination being used. Reduce impression pressure, repack to manufacturer specifications.
Blankets is too tacky. Consult blanket manufacturer. Treat blanket or change to a less tacky blanket. Check blanket wash.
Ink is too tacky for stock being run. Consult ink manufacturer to lower tack of ink.

Problem

Cause

Solution


PILING

Build o paper coating, lint or ink on rollers, blankets or plates

PAPER :

See PICKING / LINTING

INK :

See PICKING / LINTING
Ink is water logged due to insufficient body or tack. Reduce dampener settings. Consult ink manufacturer.
Ink is poorly ground, contains a coarse heavy pigment. Consult ink manufacturer. Have ink reworked or reformulated.
Improper packing of cylinders or rollers not set correctly. Check specifications and adjust it necessary.

Problem

Cause

Solution

PLATE BINDING
(LOSS OF IMAGE) Part or all of image on plate does not take ink
MECHANICAL :  
Excessive amount of lint being deposited on place. Refer to PICKING/ LINTING
Excessive plate - to - blanket pressure causing plate wear. Re-set to specification. Use packing gauge to check pressure.
Improperly set ink and dampening form rollers. Roller could be to hard check durometer. Also check setting; re-set if too much pressure exists.
Abrasive particles destroying image. Check ink grind, fountain solution, solvents, etc. Replace all contaminated material.
CHEMICAL :  
Too much acid in the fountain solution. Check pH/ conductivity and adjust to 4.0 - 4.5 pH.
Too much gum in fountain solution. Re - etch plate and rub up image areas with press ink. Drain fountain solution and refill with tap water. If image returns, replace tap water with fountain solution containing less gum.
Plate cleaners and / or scratch removers have dried on plate image. Always rinse plate thoroughly and immediately after using such item.
Detergent remains or has somehow entered the fountain system. Make sure that all parts that comes in contact with cleaning detergent have been thoroughly rinsed before reinstalling in press.
Ink will not adhere to image area due to excess amount of fountain solution being accepted by the ink. Reduce dampener setting to minimum, if problem persist consult ink manufacturer.
Plate not completely developed; gum remains on image areas. Wash plate. If problem persist have plate remade.

Problem

Cause

Solution

PLATE WEAR
Gradual loss of image area.
Improperly processed plates. Check plate developing process include Stouffer scale. Check for excess Diazo on plate preventing complete development.
Ink and / or water form rollers improperly set. Adjust to manufacturer's specification.
Excessive linting. See PICKING / LINING.
Fountain solution too concentrated. Check conductivity and reduce to proper amount.
Improperly packed plate and blanket cylinders. Check with Colight or Baldwin guage and set to manufacturer's specification.
Running plate far beyond their capabilities. Switch to higher quality plate which will result in longer plate life.
Using extremely strong inks - starvation of image area. Reduce strength of inks to improve plate lubrication.
Extremely poor grind of ink. Consult ink manufacturer to check ink grind.
Form rollers too hard. Replace form rollers.

Problem

Cause

Solution

REGISTER
After the press has beeb set for proper registration, some condition prevention consistently good register, either in the press running direction, or side -to-side
Register problems can be caused by poor alignment of press, plate, blanket, paper or film. If after checking these elements the problem persists, contact our press supplier.

Problem

Cause

Solution

ROLLER STRIPPING
Rollers do not accept inks.
Fountain solution too acid. Check pH/ conductivity level and adjust to 4.0 - 4.5 pH.
Too much water being run. Reduce dampener setting.
Desensitized metal vibrator rollers. Clean rollers, copperize, wash thoroughly. Then ink rollers and wash again.
Glazed form roller. Remove rollers from press and deglaze per manufacturer's procedures. Rinse thoroughly.
Excessive gum in fountain solution. Copperize rollers. Use less gum in fountain solution. Too much gum combined with too much acidity can cause gum to precipitate on to rollers.
Ink too strong. Consult ink manufacturer for adjustment.
Ink too water resistant. Consult ink manufacturer for adjustment.

   

RUBBING AND SCUFFING
Printed ink film appears dry but exhibits poor rub and / or scratch resistance when abraded
Too much water run on job or paper contains too much water. Reduce dampener settings. Change paper.
pH of fountain solution too high. Check pH/conductivity and adjust to 4.0 - 4.5 pH.
Ink not fully dry. See DRYING.
Roughness of paper surface creates poor rub between un printed paper surface and printed paper surface (e.g. some dull coat type stocks). Consult ink manufacturer to provide ink with better rub resistance.
Too much ink. Lower level of ink carried.
Ink is not properly formulated or rub resistance. Consult ink manufacturer for adjustment.
Insufficient binding vehicle in ink. Consult ink manufacturer for adjustment.

Problem

Cause

Solution

SCUMMING
The non - image area of lithographic plate accepting ink random area.
Low alcohol content in dampening system. Bring alcohol content to correct concentration.
Glazed blanket, ink rollers, or dampening rollers. Clean thoroughly and recondition per manufacturer's instruction.
Excessive printing pressure. Make on - press adjustment to proper pressures.
Ink body too greasy; ink spreading in to non - printing area. Consult ink manufacturer to assure ink is on standard reformulate if necessary.
Plate improperly exposed to light after being allowed to dry. Desensitizer or remake plate.
High dichromate fountain solution. Check fountain solution and adjust accordingly.
Ink too soft. Replace with stiffer ink or consult ink manufacturer to reformulate if for heavier body.
Fountain solution pH out of balance. Check fountain solution pH/ conductivity and adjust to 4.0 - 4.5 pH.
Poorly adjusted or warn dampening rollers. Adjust pressure to specification; replace cover.
Overheated ink rollers. Check for warn bearings, adjust roller pressure if necessary.

Problem

Cause

Solution

SET - OFF / BLOCKING
SET - OFF - Ink transfer to the back side of the sheet on top of it.
BLOCKING
Sheets in a bundle or load stick together
Ink too slow setting. See DRYING.
Insufficient spray powder. Increase powder application.
Lift too heavy. Run shorter lifts; tray the lifts.
Rough handling of loads Do not drop or jack loads.

Problem

Cause

Solution

SLINGING
Ink being thrown from rollers or filaments
Too much in on rollers. Make press adjustment to decrease amount of ink carried. Consult ink manufacturer to increase ink strength and carry less ink on rollers.
Improper ink and water balance, resulting in emulsification. Adjust ink an water balance.
Ink is too long in body. Consult ink manufacturer.
Rollers are incorrectly set or in poor condition. Reset rollers based on manufactured's specifications. Replace rollers if in poor condition.

Problem

Cause

Solution

SLURRED OR DOUBLE IMAGE
Dots have shadows, and reverse letters fill in.
SLURRED IMAGE - dots appear elongated or smeared, occurs on a single unit.  
Over or under packed cylinders, resulting in different speeds between cylinders, causing slippage. Adjust packing to equalize diameters of cylinders.
Lose, uneven or soft blanket. Tighten blanket clamps, adjust packing or replace blanket.
Excessive play in gears and debearing of plate and blanket cylinders. Adjust according to manufacturer's specification.
Too much pressures between plate and blanket cylinders when running smooth plates at high speeds. Use "Kiss " impression, check form roller stripe or uniformity and width.
Running too much ink on coated stock. Reduce amount of ink, then adjust water feed if necessary to maintain color density.
DOUBLE IMAGE - Second image appears along side first; occurs on multiple units.  
Improper slipper settings. Adjust packing to equalize diameters of cylinders.
Unstable paper: paper is tanning in successive units. Check ink / water balance; adjust water to minimum possible.
Loose plate. Check plate and secure.
Loose blanket. Tighten blanket clamps, adjust packing or replace blanket.

Problem

Cause

Solution

TINTING / TONING
Fine particles of ink transmitted by press water dampener to non - image areas of plate
Ink bleeding in to fountain solution. Check concentration of alcohol or alcohol substitute in fountain solution. Consult ink manufacturer to reformulate .
Improper fountain solution concentration. Check pH/ conductivity and adjust to 4.0 - 4.5 pH.
Improper ink and water balance. Adjust to proper ink and water balance.
Too much pressure between plate and blanket. Check and re- set to manufacturer's specification.
Improper setting or durometer of dampener or ink rollers. Check and re - set rollers to manufacturer's specification; if rollers are old, check durometer.
Ink not sufficiently water resistant. Consult ink manufacturer to be sure ink is on-standard. Reformulate if necessary.
Plate improperly exposed, developed. Check platemaking procedure; correct if necessary.
Prolonged use of a detergent, wash - up solution. Wash up, remove detergent with water or petroleum solvent and change solution.
Paper coating contaminating the ink train Use low tack ink, low water setting, and low pressure setting.

Problem

Cause

Solution

TRAPPING
Cannot achieve good color coverage
Tack of inks out of sequence. Make sure inks are of successively decreasing tacks.
Strength of ink improperly balanced. Each succeeding ink should carry a heavier film for optimum trap.
Improper ink viscosities. In general each succeeding color requires a lower viscosity ink.
Hue error or grey balance not keyed to color separations. Have suppliers coordinate efforts.
Unequal press stability of links. Ink tacks up quicker than preceding ink. Consult ink manufacturer to coordinate stability of all ink color(s).
Ink contains additive that creates a film preventing succeeing ink layers from adhering. Consult ink manufacturer. See CRYSTALLIZATION.
Ink and water balance. See MOTTLED SOLIDS.
Poor ink release from blanket. Consult blanket and/or ink manufacturer.
Improper register causing poor appearance. See MISREGISTER.
Process color prints do not match supplied proofs. See INCONSISTENT COLOR REPRODUCTION No. 2.

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