The Print & Packaging Glossary · N to Z

PackagingThe quantity of product in a package, declared on the label as weight (grams, kilograms), volume (millilitres, litres), or count (number of units). Under India's Legal Metrology Rules, net quantity must be declared on the principal display panel in figures at least as large as specified in the Rules based on package size. See India Packaging Regulations.

PaperFluorescent compounds added to paper coatings that absorb UV radiation and re-emit it as visible blue-white light, making the paper appear brighter and whiter under UV-containing lighting. OBAs affect spectrophotometric measurements, the M1 measurement condition (D50 illumination) correctly accounts for OBA fluorescence. See Spectrophotometer.

OffsetA planographic printing process based on the chemical repulsion of oil and water. The printing plate is flat, image areas are treated to be ink-receptive (oleophilic), non-image areas to be water-receptive (hydrophilic). Ink transfers from the plate to a rubber blanket and then to the substrate. The dominant process for commercial and packaging print worldwide and in India. See Offset Printing.

PaperThe degree to which a paper resists show-through, how opaque it is when printed on both sides. Measured as the ratio of the reflectance of a single sheet over black to its reflectance over white. Higher opacity reduces show-through in double-sided printing. Heavy-coverage jobs and thin papers require higher opacity specifications. See Paper Measurement Tools.

Pre-PressWhen one ink layer prints on top of another without knocking out the underlying colour, the two inks mix optically. Black text and keylines are typically set to overprint to prevent misregister gaps. White elements must never be set to overprint, white overprint is invisible in the final print. Varnish and UV coating layers are always set to overprint. See Trapping & Overprint.

PackagingThe rate at which oxygen passes through a flexible packaging film, measured in cc/m²/day. A critical barrier property for food packaging, products sensitive to oxidation (snacks, coffee, meat) require low OTR laminates. Aluminium foil provides the lowest OTR (near zero). EVOH and PVDC are polymer barrier materials providing good OTR at lower cost than foil. See Flexible Packaging.

ColourA proprietary colour communication system used worldwide for specifying, matching, and communicating colours in print. Pantone spot colours are produced from pre-mixed inks matched to a physical swatch book. The Pantone Solid Coated (C) range is used for specifying colours on coated paper. Always specify the full Pantone reference number, e.g. Pantone 485 C. See Pantone & Spot Colours.

Pre-PressAn ISO-standardised subset of PDF designed for reliable print file exchange. PDF/X-4 (the current recommended standard) supports live transparency and CMYK plus spot colours. All fonts must be embedded, an output intent ICC profile must be included, and all images must be at production resolution. See Designing for Offset.

FinishingA binding method where pages are gathered, the spine is ground to create a rough surface, and a flexible adhesive is applied to bond the pages to a separate cover. Used for books, catalogues, and thick brochures (typically 60+ pages). PUR (polyurethane reactive) adhesive provides stronger binding than EVA hotmelt. See Binding.

OffsetPrinting both sides of a sheet in a single pass through the press. Perfecting presses use a special turning mechanism (perfector unit) to flip the sheet between the front and back printing units. Alternatively, work-and-turn or work-and-tumble imposition schemes print both sides in two press passes without changing the plate.

OffsetA logarithmic scale measuring acidity (below 7) or alkalinity (above 7) of a solution. In offset printing, the fountain solution pH must be maintained at 4.5–5.2 for correct ink-water balance. pH below 4.0 causes ink drying problems; pH above 5.5 causes scumming and tinting. Measured with a calibrated pH meter before each press run. See Fountain Solution.

InkA chemical compound in UV-curable inks and coatings that absorbs UV radiation and initiates the polymerisation (curing) reaction. Some photoinitiators (notably ITX and benzophenone) can migrate through packaging materials into food. For food-contact packaging, only low-migration photoinitiators with confirmed compliance to relevant food contact regulations may be used. See Food-Safe Inks.

OffsetA press defect in which small pieces of the paper surface (fibres, coating particles) are pulled off by high-tack ink and adhere to the blanket. Causes voids in subsequent impressions and contamination of ink rollers. Prevented by matching ink tack to paper surface strength, and by avoiding excessively high tack inks on low-strength uncoated papers. See Print Defects Guide.

InkThe solid colourant in a printing ink, insoluble particles dispersed in the ink vehicle. Pigments determine the hue, tinting strength, lightfastness, and chemical resistance of the ink. Organic pigments are used for most process and spot colour inks. Inorganic pigments (titanium dioxide, iron oxides) are used where opacity or specific chemical resistance is required. See Offset Inks.

Pre-PressThe image carrier in offset printing, a thin aluminium sheet coated with a light-sensitive or thermally sensitive polymer layer. The plate is exposed in a CTP platesetter, processed to reveal image and non-image areas, and mounted on the plate cylinder of the press. One plate per colour per press pass. See Printing Plates.

Pre-PressThe resolution of a digital image, the number of pixels per linear inch at a given print size. For offset printing at 175 LPI, the minimum effective PPI at the final print size is 263 PPI (1.5× screen ruling). Standard specification: 300 PPI at final print size. Placing an image at 200% of its original size halves the effective PPI. See Designing for Offset.

Pre-PressAll operations that prepare a digital file for production printing, file receipt and checking, preflight, colour management, trapping, imposition, RIP processing, proofing, and plate output. Pre-press is the critical link between design intent and press output. See Pre-Press Complete Guide.

Pre-PressThe automated and manual checking of a print file before production to verify that it meets all technical requirements, correct colour mode, embedded fonts, sufficient image resolution, correct bleed, no overprint errors, and correct PDF/X compliance. In InDesign: Window → Output → Preflight. See Pre-Press Complete Guide.

MeasurementSee K value. The densitometric measurement of contrast between solid and shadow tones. Minimum 35% on coated paper for acceptable shadow detail. See ISO 12647-2.

ColourThe four standard printing inks (Cyan, Magenta, Yellow, Black) used in combination to reproduce a full colour range. Distinct from spot colours, which are pre-mixed inks printed as additional colour units. See CMYK.

ColourThe updated ICC output profile for offset printing on coated paper, replacing ISOcoated_v2 (Fogra39). Based on more recent press characterisation data and requires M1 measurement condition. Increasingly specified for new jobs, particularly for EU export markets. Available free from eci.org. See Colour Management.

FinishingA perfect binding method using polyurethane reactive adhesive instead of standard EVA hotmelt. PUR provides significantly stronger and more flexible binding, better performance at temperature extremes, and improved adhesion to coated papers and challenging substrates. Premium specification for high-quality books and catalogues. See Binding.

PackagingA polymer coating applied to PVC blister film to provide barrier properties against moisture and oxygen transmission. PVDC-coated PVC (e.g. Aclar equivalent) is the standard lidding film for pharmaceutical push-through blister packs requiring high moisture barrier performance. See Blister Packaging.

PackagingA two-dimensional matrix barcode that encodes data as a pattern of black and white squares. QR codes can encode URLs, text, and other data. In packaging, used for consumer engagement (linking to product information, recipes, authenticity verification) and increasingly for serialisation and track-and-trace applications. ISO 18004 governs QR code specification. See Barcode Guide.

PackagingThe blank space required on either side of a barcode (and at top and bottom for 2D codes) that is free of all design elements. The quiet zone is essential for reliable barcode scanning, any design element within the quiet zone may cause scanner misread. EAN-13 quiet zones at 100%: left margin 3.63mm, right margin 2.31mm. See Barcode Guide.

OffsetThe accurate alignment of one printed colour relative to all other colours. In four-colour process printing, all four CMYK separations must be in register for the halftone dots to overlap correctly and produce clean colour. ISO 12647-2 specifies ±0.1mm maximum misregister for coated paper offset. See Register.

ColourThe algorithm used by the colour management system to handle out-of-gamut colours when converting between colour spaces. Four intents defined by ICC: Perceptual (compresses all colours proportionally, good for photographs), Relative Colorimetric (clips out-of-gamut colours, standard for proofing to ISO), Absolute Colorimetric (preserves paper white simulation, used for soft proofing), Saturation (maximises saturation, for business graphics). See Colour Management.

Pre-PressThe technical processes involved in preparing and reproducing artwork for print production, scanning, colour separation, retouching, imposition, and plate output. A term that predates digital production but still used to describe the pre-press function in many Indian press rooms.

Pre-PressText that appears as a white (or light) colour knocked out of a dark background. Reversed text requires larger minimum sizes than positive text because ink spread reduces the white letterform counters. Minimum reversed text: 8–9pt in bold sans-serif for offset; 8pt for flexo. See Typography for Print.

Pre-PressA deep black achieved by combining CMYK inks rather than using K (black) alone. Standard rich black build: C60 M40 Y40 K100 (total ink coverage 240%). Produces a denser, more even black on large areas than 100K alone. Must not be used for body text below 18pt, the multi-channel build causes visible colour fringes from any misregister. See Designing for Offset.

Pre-PressThe software that converts a digital print file (PDF/X-4) into a rasterised bitmap at the required resolution and screen ruling for the platesetter or digital press. The RIP applies halftone screening, colour management, trapping, and other production parameters before outputting to plate or digital press. See Pre-Press Complete Guide.

MeasurementA quality test that simulates abrasive handling of a printed surface by rubbing a defined weight over a defined number of strokes. Evaluates the scuff resistance of ink, varnish, and lamination. Standard: TAPPI T830, ISO 11628. Test weights: 2 lb (standard) or 4 lb (aggressive). See Adhesion & Rub Testing.

FinishingA binding method where printed sections are folded, collated, and stapled through the spine with wire staples. The most economical binding for publications up to 64 pages. Requires page counts in multiples of 4. See Binding.

Pre-PressThe zone inside the trim line where all critical design content (text, logos, barcodes) must be placed to ensure it is not cut away during finishing. Standard commercial print safety margin: 5mm from the trim on all sides. For business cards: 3mm minimum. See Designing for Offset.

PaperA premium carton board manufactured entirely from bleached chemical pulp, providing a bright white, clean surface on both sides. Superior food safety profile (no recycled fibre), excellent printability, and clean crease performance. The standard board for pharmaceutical cartons in India. See Paper & Board Grades.

ProcessA printing method that forces ink through a mesh screen onto the substrate. A stencil on the screen blocks ink in non-printing areas. Screen printing deposits the thickest ink films of any printing process (10–80 microns), making it the only process that can print opaque white on dark substrates. See Screen Printing.

Pre-PressSee LPI. The number of halftone dot rows per linear inch. Determines the fineness of halftone reproduction. Must be matched to the substrate surface quality. See Screen Ruling.

OffsetAn offset press defect in which ink deposits in non-image areas, producing an overall tint or visible ink in background areas. Caused by fountain solution pH too high (alkaline), incorrect ink-water balance, or plate contamination. The most common defect arising from fountain solution pH drift above 5.5. See Print Defects Guide.

OffsetTransfer of wet ink from the front of one sheet to the back of the sheet above it in the delivery pile, before the ink has dried. Produces a mirror image of the print on the reverse of sheets. Prevented by anti-setoff powder, controlled ink coverage, adequate delivery pile height management, and correct ink formulation. See Anti-Setoff Powder.

Pre-PressA group of pages printed on a single sheet that when folded produces a section of a book or booklet. Signatures are always in multiples of 4 pages (4pp, 8pp, 16pp, 32pp). Multiple signatures are gathered (collated) to form a complete publication. See Imposition.

ColourAn on-screen simulation of the printed output using ICC profiles, showing how the artwork will appear when printed on a specific press and substrate. Requires a hardware-calibrated monitor. In Photoshop: View → Proof Colors. Soft proofing cannot replace a physical contract proof but allows rapid iteration during design. See Proofing.

FinishingA BOPP lamination film with a micro-textured matte surface that produces a distinctive velvet-like tactile feel. Very low gloss (5–12 GU at 60°). Highly susceptible to fingerprinting and scuffing, requires careful handling after application. Premium specification for luxury packaging, cosmetics, and high-end commercial print. See Lamination.

MeasurementAn instrument that measures the complete spectral reflectance of a surface across the visible wavelength range (380–730nm). From spectral data, calculates colorimetric values (L*a*b*, ΔE). The instrument for colour verification, ICC profile building, proofing system calibration, and brand colour conformance. See Spectrophotometer.

ColourA pre-mixed ink printed from a dedicated ink unit rather than built from CMYK process inks. Spot colours achieve more accurate and consistent colour matching than CMYK simulation, particularly for brand colours, metallic inks, fluorescents, and any colour outside the CMYK gamut. See Pantone & Spot Colours.

FinishingUV varnish applied selectively to defined areas of a laminated surface (typically over a matte lamination base) to create a high-gloss contrast effect. The UV coating is applied via a silk screen or letterpress unit. Typical spot UV gloss: 85–100 GU at 60°, against 8–18 GU matte base. Contrast ΔGloss ≥65 GU is the minimum for visible effect. See Varnishes & Coatings.

Pre-PressA press sheet size of 320×450mm, the standard press sheet for B2 format sheetfed offset in India. Slightly larger than A3, providing space for bleed, grippers, crop marks, and colour bars around the A3 finished print area. Most Indian commercial press rooms use SRA3 as their standard sheet. See Paper Sizes.

PaperAny material on which printing is applied, paper, board, film, fabric, metal, glass, or plastic. The choice of substrate affects process selection, ink formulation, lamination specification, and finished product performance. Coated paper and board are the most common substrates in Indian commercial and packaging print.

PackagingA measure of a substrate's ability to be wetted by inks and adhesives, expressed in dynes/cm. Polymer films (BOPP, PE, PET) have low natural surface energy and must be corona- or flame-treated to raise it to ≥38 dynes/cm for adequate ink adhesion. Verify with dyne pens before printing on film substrates. See Labels.

InkSee Ink tack. The resistance of an ink film to splitting. High-tack inks transfer well from smooth coated papers but may cause picking on rougher stocks. See Offset Inks.

Pre-PressThe sum of all CMYK ink percentages at any point in a design, expressed as a percentage. TIC = C% + M% + Y% + K%. Maximum TIC for coated paper: 300%. Maximum for packaging board: 280%. Exceeding TIC limits causes slow ink drying, setoff, and lamination failures. Check in Photoshop soft proof or InDesign Output Preview. See Designing for Offset.

OffsetSee Scumming. Ink contamination of non-image areas, producing an overall tint on the printed sheet. Caused by fountain solution pH imbalance. See Print Defects Guide.

MeasurementSee Dot gain. The increase in the halftone dot area from the file value to the printed value. TVI = printed dot area − file dot area. ISO 12647-2 target: 18% TVI at 50% screen for coated paper. See ISO 12647-2.

Pre-PressA pre-press technique that creates a small overlap zone between adjacent colours to compensate for misregister in printing. Without trapping, slight misregister between adjacent colour separations reveals a white gap between the colours. Trap values: offset 0.05–0.1mm, flexo 0.3–0.5mm, gravure 0.2mm. See Trapping & Overprint.

Pre-PressThe cutting line that defines the final size of a printed piece after guillotining. Indicated by crop marks in the slug area. The document page size in InDesign should be set to the trim size, bleed extends beyond this boundary. See Designing for Offset.

MeasurementSee Dot gain. Abbreviation for Tone Value Increase. See ISO 12647-2.

PaperPaper without a mineral coating layer. More absorbent than coated paper, producing more dot gain and lower colour saturation. Higher bulk than coated paper at the same GSM. Used for stationery, letterheads, books, and any application where a natural, tactile surface is preferred over the high-gloss reproduction of coated stock. See Paper & Board Grades.

InkThe process by which UV-curable inks and coatings are instantly hardened by exposure to ultraviolet radiation. UV radiation activates photoinitiators in the ink, triggering polymerisation, the ink converts from liquid to solid in a fraction of a second. UV-cured inks cannot re-wet or set off after curing. See UV Printing.

ProcessPrinting using UV-curable inks that are instantly dried by exposure to UV lamps immediately after impression. Enables printing on non-absorbent substrates (plastics, foil, glass), very high gloss effects, and immediate finishing without waiting for ink drying. LED-UV is the energy-efficient modern variant. See UV Printing.

DigitalThe ability to change text, images, or barcodes on each individual printed item within the same production run using digital printing technology. Applications include personalised direct mail, numbered certificates, serialised pharmaceutical packaging, and loyalty cards. Not possible with conventional plate-based offset printing without significant re-setup. See Digital Printing.

FinishingA clear coating applied over printing to protect the surface and modify its appearance. Types: oil-based varnish (inline, applied by a press unit), aqueous varnish (water-based, inline or offline), UV varnish (UV-cured, highest gloss). See Varnishes & Coatings.

InkThe resistance of a fluid to flow, the thickness or flow resistance of an ink. Offset inks are relatively viscous (paste inks). Flexo and gravure inks are low-viscosity fluid inks. Viscosity affects ink transfer, levelling, and drying behaviour. Controlled by temperature and solvent content in flexo/gravure. Measured with a Zahn cup (flexo/gravure) or an inkometer (offset). See Offset Inks.

InkOrganic chemicals that evaporate readily at room temperature and contribute to air pollution and health concerns in production environments. Solvents in flexo and gravure inks are the main source of VOC emissions in print. IPA in fountain solution is a VOC source in offset press rooms. Environmental regulations and FSO 14001 compliance drive reduction of VOC use in Indian press rooms. See Sustainability.

InkAn ink formulation using water as the primary solvent/vehicle instead of petroleum-based mineral oils or organic solvents. Used in flexo and gravure printing for food packaging applications where VOC emissions and residual solvents must be minimised. Provides lower residual solvent levels than solvent inks but may have lower colour density and require more care with substrate surface energy. See Types of Inks.

OffsetPrinting from a continuous roll (web) of paper rather than individual sheets. Web offset presses run at much higher speeds than sheetfed presses and are used for high-volume publications (newspapers, magazines, catalogues) where run lengths justify the higher setup costs. Heat-set web offset uses ovens to dry inks rapidly; cold-set uses newsprint absorption.

Pre-PressAn imposition scheme in which both sides of the printed piece are printed on one side of the sheet from a single set of plates, then the sheet is turned over sideways (rotating around the vertical axis) and printed again from the same plates. The sheet is then cut in half to produce two finished pieces. Efficient for smaller format work on larger sheets. See Imposition.

Pre-PressThe height of lowercase letters without ascenders or descenders in a typeface, measured from the baseline to the top of the letter 'x'. X-height is a better indicator of a typeface's legibility at small sizes than point size alone, a typeface with a large x-height appears larger and more legible at the same point size than one with a small x-height. Relevant when specifying minimum text sizes for regulatory content on packaging.

InkThe Y in CMYK. Yellow ink appears at lower measured optical density than cyan or magenta at equivalent ink film weights because of the spectral response of the yellow pigment and the blue density filter. ISO 12647-2 target density for yellow on coated paper: D 1.05 (Status E), significantly lower than the 1.45 target for cyan and magenta. This is correct, not a specification error. See ISO 12647-2.

OffsetA controllable section of the offset press ink duct that regulates ink flow across the width of the press sheet. Modern presses have 16–32 independently adjustable ink zones per colour unit. Zone adjustments are the primary method by which press operators control ink density across the sheet to match the colour bar readings to the target values. See Offset Printing.