Substrate
A
First stage of drying when printing on porous materials.
B
The milky veil, which may appear on the surface of some prints, usually caused by the too rapid evaporation of the solvent in an ink resulting in condensation of moisture on the ink surface.
C
Describes the effect when an ink can be rubbed off after drying. It indicates a lack of cohesion in the ink due to insufficient binder, over-dilution or incorrect formulation for printing on the mater...
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The purity or intensity of a colour.
The dry weight per unit area of an ink or other type of coating.
Blue-green, one of the primary process colours. See process printing and primary colours.
D
In relation to inks, density refers to the extent to which a layer of ink has absorbed unwanted colours from white light. Thus a print with low density has absorbed unwanted colours only slightly and ...
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The solvent or solvent mixture used to reduce the viscosity (i.e. to thin) an ink.
An ink or other type of coating in which a solid constituent that is not soluble in the liquid medium is pre-ground so that the particles are fine enough to remain in the suspension liquid.
A method of testing the colour of an ink where a small quantity of the ink to be tested is taken up on the tip of a hand-held scraper-blade and drawn out on a sheet of the material to be printed.
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E
Compound formed when hydrogen in an acid is replaced by an organic radial such as ethyl.
An organic solvent, often used in conjunction with industrial methylated spirit that is frequently incorporated in flexo ink formulation.
A resin solvent mixture without dyes or pigments that is used for reducing the colour strength of an ink while maintaining the same percentage of solids so that the printing qualities are not impaired...
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F
Usually used in the expression “colour fastness” with reference to the resistance of an ink to fading under exposure to light.
The gloss of a print or the surface of a material.
H
The name of a colour. See Shade, Tint, Tone and Chroma.
A range of solvents either aliphatic or aromatic, used in the formulation of inks.
I
The bond between ink and the material on which it is printed, when subjected to rubbing and crinkling.
In relation to an ink, refers to the strength of the colour.
L
This term is used for inks that will not fade to a significant extent even after prolonged exposure to light.
M
Blue-red: one of the primary process colours. See Process printing and Primary colours.
Coloured sample, usually printed, the colour of which is considered to be sufficiently close, i.e. within commercial tolerances, to the colour of another sample.
Another word for extender – an ink without the addition of dyes or pigments which is therefore colourless.
The change in the appearance of colours according to the spectral composition of the light under which the colours are viewed. A special case is where two colour samples match under a particular light...
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TThe movement of solvent or colour from one layer of composite material to another layer.
O
Opaqueness, resistance to the passage of light – a word applied to the density of an ink printed on a transparent film.
Chemical compounds e.g. solvents containing carbon in their molecules.
A varnish applied over print to improve gloss, to improve resistance to abrasion or to modify slip.
P
The extent to which a material will permit the passage of water vapour or gases.
The pulling of the web surface by an ink that is too tacky, particularly in the cases of printed paper when fibres may be pulled off from the paper by the inked plates.
Minute spots that remain unprinted. Possibly due to ink drying in the cells of the anilox or due to the surface being printed lacking in receptiveness.
The extent to which a material or a surface is porous, i.e. containing minute holes or passages that can absorb or transmit fluids and water-vapour.
The pre-treatment (usually humidification to increase moisture content) of a web before printing – often carried out in-line. It can also refer to pre-heating to assist adhesion of inks or to he...
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The colours of the spectrum which when combined make white light. To be strictly correct the primary colours are orange shade of red, blue and green because these are the colours of the rays that when...
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R
The odour of a printed material after drying, usually resulting form residual solvent not removed by the drying process but may be due to overheating the resin incorporated in the ink.
Slow drying solvents used for reducing the drying rate of an ink.
A print fault where the ink runs into lines, possibly due to over-thinning of an ink with solvent.
The science and study of the deformation and flow of matter.
S
The ability of an ink to resist removal by scratching or rubbing.
Testing a printed surface by placing it on a smooth hard plate and rubbing to see if any of the ink is removed.
The tendency of an ink in a trough to form a scum of skin due to exposure to air without sufficient agitation.
The word is often used loosely when referring to any variation of a colour but more strictly it means the variation of a colour by the addition of black. Thus maroon is a shade of magenta. See Tint, T...
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The volatile liquid in which dyes and resins are dissolved and pigments are dispersed to produce printing ink.
The change in the character of an ink due to the addition of diluents during use that disturb the solvent balance, or the greater evaporation of one component of the solvent mixture or moisture pick-u...
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Apart from the common meaning of material being held in store, the word may have the same meaning as ‘base material’ or ‘raw material’, e.g. as in ‘paper stock’. It...
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The base material being printed.
A range of colour samples differing in hue and other aspects by small steps.
T
The variation of a colour brought about by the addition of white.
V
The property of a fluid whereby it tends to resist relative motion within itself. If different layers of a fluid are moving with different velocities, viscous forces come into play, tending to slow do...
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W
The material that is threaded, i.e. guided by rollers, through a machine for processing.
The extent to which a material can be wetted evenly by an ink. A material can be tested for wettability by dabbing ink on the surface and checking whether it spreads out (indicating good wettability) ...
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Z
A type of cup used for the measurement of the viscosity of an ink by measuring the time taken for ink to empty through a small hole in the base if the cup. A Zahn No. 2 cup is usually used. Alternativ...
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