PRINTING INDIA

Heading	Problem	Solution
Drying too fast
Drying too fast on rollers - rollers
get tacky and this creates possible	Too much drier in ink.	Consult Ink Manufacturer.
picking and tacky poor, uneven
print which becomes worse with	Too fast type of solvent used in ink	Consult Ink Manufacturer.
continued running.	and solvent is evaporated or absorbed
	by rollers.

	Rollers set too tight, generating	Adjust rollers to proper
	excess heat or roller train.	pressure.

	Press room too hot.	Improve air circulation in
		press room.

Drying too slow

Drying too slow- conventional inks do
not dry in 4 to 8 hours and prints	Not enough drier in ink.	Add proper drier to ink
mark and rub easily.		Consult to Ink Manufacturer.

	Too much anti-oxidant in ink.	Add drier and good drying
		vehicle. Consult Ink
		manufacturer.

	Too much non-drying oils or	Consult Ink Manufacturer.
	compounds in ink.

	Stock too acidic.	Test stock for drying
		properties before running
		Add drier stimulator to
		water.

	Stock contains excess moisture.	Use heater on delivery or
		store stock in warm place
		prior to running.

	Fountain solution is too acidic.	Correct pH of fountain
		solution.

	Driers absorption in ink on aging.	Add driers to ink replace
		lost driers.

	Ink taking up too much water and	Consult Ink Manufacturer.
	emulsifying.



Piling

Pilling- ink piles on rollers, plate or
to blanket and fails to transfer	Ink is too short, not water-repellent	a. Add a varnish that will
properly the substrate.	enough.	lengthen the ink and
		improve water resistance.
		b. Reduce dampening water
		to a minimum. Add some
		alcohol to fountain solution.
		c. If this does not help,
		remake ink with more
		water-resistant varnish.

	Ink is poorly ground. Particles are	Have ink reground. Consult
	transferred and build on rollers, plate	Ink Manufacturer.
	and blanket.

	Excessive use of heavy opaque tend	Use a more transparent ink.
	pigment in ink, the particles of which
	to pile.

	Too much water and ink being carried	Cut down on water and ink
	ink to emulsify.	feeds to obtain a proper
		balance.

	Stock coating adhesive is too water	a Press size paper with
	soluble and coating is softened by	transparent white ink
	first units and coating is then picked	b Change to a better
	up on the blanket of later units.	paper.

	Ink tacks up too rapidly on the stock	Add alkyd to ink to slow
	and piles on later units blankets.	down setting.



Mottling

Mottling- solid areas appear, type
or grainy. Pinholes of white paper	Too much water.	Reduce water if possible.
specked showing through. Edges of
slurred and uneven.	Too much water in a prior unit.	Reduce water on prior unit if
		possible.

	Weak stock or paper coating is too	Reduce with proper reducer
	soft.	and reduce press speed if
		necessary.

	Improper pressure between blanket and	Reduce pressure to minimum
	stock (excessive).	between blanket and stock.

	Loose spots in paper coating.	Change stock or press size
		sheets.

	Blanket too hard.	Change to a softer blanket.

	Insufficient water at the plate.	Increase water if possible.

	Ink too strong and insufficient ink is	Weaken ink to allow more
	being carried.	ink to be carried on sheet.



Image Sharpness

Sharpness of image- image
working too sharp. (Wearing of	Ink too tacky.	Reduce tack.
plates). Fine lines and dots tend to
disappear. Print loses clarity,	Fountain solution is too acidic.	Check pH and adjust if
litho printing becomes weak and		necessary.
streaked.
	Ink sufficiently water-repellent and	Add water-repellent varnish
	washes out.	to ink.

	Pressures between plate and blanket	Reduce pressure to minimum
	too heavy.	between plate and blanket.

	Improper form roller setting.	Check and reset form rollers.

	Starving Plate of ink.	Weaken ink and carry more
		to protect image.

	Poorly ground ink wears plate.	Have ink reground. Consult
		Ink Manufacturer.



Hickies

Hickies- defects in a print
appearing as specks surrounded	Particles of dried ink skin or drier mixed	Only remedy is prevention.
by an unprinted halo. Caused by	into ink due to careless ink making or
particles of dried ink, particles from	careless handling in press room.
decomposing rollers dirt, plaster, or
accumulation of paper dust.	Paper dust and spray powder	Good housekeeping around
	contaminating ink on rollers.	the press is essential. Clean
		the feed board and delivery
		grippers frequently to
		spray remove paper dust
		and powder. Use hot water
		wash-up on rollers and
		blankets.



Ghosting

Ghosting- image patters appear
in solids. Ink is removed from roller	Poor distribution of ink.	Ensure ink has good flow.
by image in front of a solid and ink		Add alkyd varnish to improve
cannot be replaced or redistributed		flow.
prior to print solid.
	Ink over-pigmented (too strong).	Avoid running colors too
		heavy to produce tints.
		Make ink weaker and run
		more of it.

	Faulty roller setting or poor rollers.	Check rollers setting and
		adjust if necessary.

	Ink too transparent.	If possible use opaque inks
		rather than transparent
		inks.

	Poor layout of solids.	Whenever possible make
		layout with solids well
		distributed.



Scumming

Scumming- scum forms on plate.
Hard to keep non-image areas	Ink too soft and spreads over	Add heavy bounded get -
clean. Non-image areas pick up ink.	non-image, sensitizing it.	varnish to ink. Consult ink
Thickening of images. Filling in of		manufacturer.
halftones.

	Too much ink being carried and being	Carry less ink and use a
	squashed over the non-image areas,	strong ink if required to
	sensitizing those areas.	achieve color density.

	Insufficient acid or gum in fountain	Strengthen fountain solution.
	solution.

	Faulty plate. Not opened properly.	Re-etch and gum plate on
	Plate does not desensitize.	press.

	Dirty or worn dampener covers.	Clean or re-cover dampening
		rollers.

	Wear of plate due to abrasive material	Change to a better paper.
	from the paper on the blanket.	Reduce plate-to-blanket
		pressure to minimum.

	Abrasive pigment particles in ink.	Have ink reground or
		replace with a better ink.
		Consult Ink Manufacturer.

	Plate being sensitized from image off	a. Re-etch & gum scumming
	previous units.	plate.
		b. Increase acid & gum on
		problem plate.
		c. Run ink more sparely on
		preceding units. If
		necessary, use stronger
		inks.

	Greasy metering roller in Dahlgren type	Clean rollers.
	dampening system.

	Ink is not sufficiently water-resistant	Add water-resistant varnish.
	and is broken down by fountain
	solution.

	Improper dampening setting.	Reset dampeners to proper
		setting.

	Improper form roller settings usually	Check stripe on plate and
	causes a lead-edge scum line across	adjust if necessary.
	the plate.



Tinting

Pigment breaks down in the
fountain solution causing a light	Ink is too low in viscosity to carry the	Add a high viscosity
discoloration of the non-printing	pigment.	water-resistant varnish to
areas.		the ink.

	Ink is not litho resistant.	Add a high viscosity
		water-resistant varnish to
		the ink.

	Pigment is hydrophilic and bleeds in	Reformulate ink with alcohol
	water.	resistant pigments.

	Pigment bleeds in alcohol (Dahlgren).	Reformulate ink with alcohol.

	Too much acid in fountain solution.	Check pH pf fountain
		solution and reduce acidity
		of necessary. Reduce
		amount of solution if
		possible.

	Fountain solution is extracting an	Change paper.
	emulsifier or sensitizing agent from the
	paper coating. Proof: substitution of
	another paper stops the tinting.



Chalking

Chalking - ink is dry but rubs off
easily under a little pressure.	Vehicle is too low in viscosity.	Add good drying, high
		viscosity binder.

	Insufficient binder in ink.	Add good drying, high
		viscosity binder.

	Stock is too porous.	Add good drying, high
		viscosity binder.

	Ink dries too slowly.	Add good drying vehicle.
		Add proper driers to the ink.

	a. too much anti-oxidant.	a. Add good drying vehicle.
		Add proper driers to the ink.

	b. Lack of driers.	b. Add good drying vehicle.
		Add proper driers to the ink.

	c. Poor drying vehicle.	c. Add good drying vehicle.
		Add proper driers to the ink.

	d. fountain solution is too acidic.	d. Adjust pH of fountain
		solution to above 4.

	e. paper is too acidic.	e. Add drier stimulator to
		fountain solution and
		increase driers in ink.

	f. too much fountain solution stock	Cut back amount of water
	or moisture content of stock is too	carried if possible, and use
	high.	heater in delivery if possible,
		always store stock in a dry
		location.



Poor light fastness

Color fades out when exposed to
light..	Fugitive pigment used in ink.	Use permanent inks when
		light fastness is required.



Set-off

Set-off (Offsetting)- ink
transfers or smears from printed	Too much ink carried	Use stronger ink
side of sheet to reverse side in
delivery pile.	Ink sets too slowly on stock	Use a heater to speed up
		setting Consult Ink
		Manufacturer

	Stock is too hard and solvent	Increase amount of spray
	penetration is too slow	powder

	Faulty spray settings- insufficient	Correct spray unit if
	spray being carried. Uneven coverage	necessary
	of spray

	Lifts stacked too high	Reduce size of lifts or
		increase spray. Run Sheets
		into trays

	Rough handling of printed stock or	Handle printed stock
	sheets. Poor jogger settings	carefully; reset jogger so
		that sheets do not side



Rub Resistance

Rub Resistance (Poor)- ink is dry,	Ink has only a surface dry and not a	Consult Ink Manufacturer.
but has poor adhesion under rubbing	complete through dry.
pressure.
	Ink contains insufficient wax to	Consult Ink Manufacturer.
	promote slip required to give rub.

	Not enough binding varnish in ink for the	Add additional binder
	stock run.	required for particular stock.



Stripping

Stripping- the rollers accept the
ink unevenly and areas appear	Rubber rollers are glazed.	Deglaze rollers with glaze
which are stripped of ink,		remover. Wash - up
starving the plate of ink in those		thoroughly and use hot
places.		water for final wash-up.

	Steel or copper rollers have become	a. Copperize copper rollers
	preferentially wetted by the aqueous	b. Strip the steel rollers and
	etch and repel the ink from the area.	dry well before re-inking.

	Ink is too heavy and short and has	Add alkyd varnish to ink to
	poor distribution.	improve flow and distribution.

	Ink is too strong.	Reduce strength and run
		more ink.

	Too much water being carried on plate.	Reduce dampener flow.

	Too much acid in fountain solution.	Adjust to proper pH.

	Ink takes up too much water.	Add water-resistant varnish.

	Ink does not emulsify properly.	Consult Ink Manufacturer.



Trapping

Trapping- poor in multi color wet	Too much ink carried on first down	Make first down colors as
printing. last colors do not transfer	run colors. Underneath ink-film is too	strong as possible, carry
properly to the first colors.	heavy. Underneath colors should never	very thin films. (Thin films
	heavier than succeeding ink colors.	trap better than thick films.)

	Tack sequence out of balance. First	Adjust to proper tack
	down colors should be tackier than last	sequence.
	down colors.

	Unequal tack stability of quick set inks.	Add alkyd to the unstable
	One ink tacks up quicker on rollers	ink to stabilize its tack on
	than the previous color.	the rollers.



Slurring

Slurring- shadow dots and reverse
letters fill up.	Caused most frequently by slippage	Correct poor press aided
	between cylinders or press.	condition. Problem can be
		using a stronger and heavier
		by ink, but this only masks
		the problem.

	Oil on bearers.	Correct poor press condition.

	Over packed or under-packed cylinders	Correct poor press condition.

	Slurs that show a double dot in	Correct poor press condition.
	halftones indicate improper press
	adjustment.