Glossary Of Paper Bags And Disposables

Glossary of Paper and Printing Terminology

  • Abrasiveness: The level wear resulting from friction that paper, ink and coatings cause on dies, cutting blades, plates, etc.
  • Adhesive: Cold Temperature (Cold Seal) Adhesive that will create a bond when applied to a cold surface in a cold environment.
  • Adhesive Pressure Sensitive (Peel & Seal): It is called pressure sensitive because when the adhesive comes in contact with a surface and pressure is applied to the label, the adhesive will allow the face-stock to stick.
  • Basis Weight: The weight in pounds per ream (500 sheets) in the basic size for a specific grade of paper (Fig. 1).

Figure 1. Basis weight versus paper thickness

  • Beater Dyed: A type of paper that is dyed in the manufacturing process when the material is still a slurry, resulting in a paper that is a solid color all the way through the paper (if cut or ripped, the inside of the sheet or fiber is colored the same as the outside).
  • Bleed Through: When printing from one side of the sheet is visible on the other side due to ink problems opposed to show through where the problem results from lack of opacity in the paper.
  • Broke: Machine trim or undesirable paper that is returned to the beaters.
  • Bursting Strength: The amount of uniform pressure required to pull a sheet of paper apart.
  • Calendering: A general term meaning pressing with a roll. The last operation on the drying machine before the paper is wound on reels. Machine calenders are stacks of vertical cast steel rolls that have polished ground surfaces. The paper enters the stack at the top and is compacted and smoothed progressively as it travels down the stack.
  • Close Register: When two colors fit tightly together with little or no trap allowance. This requires precise alignment when printing.
  • Die Cutting: The main method or standard means of die cutting involves the use of metal dies to give paper or substrate products specific shapes or designs that cannot be accomplished by a straight cut on a web press or a guillotine cutter.
  • Flat Bag: A bag that has no side or bottom gussets.
  • Flexography: A printing process using a raised surface on a flexible plate, often made of a rubberlike material, mounted on a rotary letterpress. Flexographic inks are very thin, watery inks that dry very quickly.
  • Flooding: Printing an entire sheet with ink or varnish.
  • Foil Stamp (Hot Stamp): A printing process where a heated die is stamped onto a sheet of foil, causing the foil to release from the backer onto the material being printed.
  • Font: A complete set of upper and lower case characters, numerals, punctuation marks, and symbols of one specific typeface, size, and style (Fig. 2).

Figure 2. Font

  • Forest Stewardship Council (FSC): An independent, international, environmentally and socially oriented forest certification organization. It trains, accredits and monitors third-party certifiers around the world and works to establish international forest management standards.
  • Full Bleed: Printing that goes to the edge of all four sides of the page.
  • Glassine: Translucent, smooth, grease-resistant paper made from highly beaten chemical pulps, subsequently super-calendered.
  • Halftone Screen: A transparent material consisting of evenly spaced lines that is placed between a photograph and the film to be exposed. The number of lines to the inch controls the coarseness of the final dot formation; The more lines used, the higher the quality. The screen that is used depends on the paper and the type of printing process used. In electronic systems, the screen is simulated by software.

Figure 3. Traditional Halftone Screen

  • Hard Copy: The printed output of an image that is displayed on a monitor. It may be output on paper or film.
  • Hickey: A spot on a printed sheet that appears as a small white circle with ink in the center, caused by particles such as dirt, dust, or bits of paper.
  • Hot Stamping: A printing process where a heated die is stamped onto a sheet of foil, causing the foil to release from the backer onto the material being printed.
  • Hot-Melt: Adhesive A solid thermoplastic material that liquefies when heated and then when it cools it re-solidifies to form a bond.
  • Ink Holdout: The ability of the paper to keep ink from absorbing into it.
  • Knockout: An opening, left in a printed area, in which a figure or photograph may be placed. Reversing type or art out of the background so that when the type or art is printed in that area it will not interfere with the color you are trying to achieve.
  • Kraft Paper: A sturdy brown paper with a high-pulp content used for wrapping paper, grocery bags, and some varieties of envelopes.
  • Kraft Process: A chemical pulping process that cooks down the tree to remove lignin, retaining the fibers for paper making.
  • Line Art: In traditional graphic arts, line art refers to pictures that use no halftones techniques and no mid-tones, just black and white. Also called line copy.
  • Liner-board: Kraft paperboard, generally unbleached, used to line or face corrugated core board (on both sides) to form shipping boxes and various other containers.
  • M (unit of measure): Abbreviation for a quantity of 1000 units.
  • Machine Direction: The direction parallel to the forward movement of material through the press.
  • Machine Finish (MF): Finish that is obtained while the paper is on the paper machine. Different finishes are obtained by the number of times the paper is passed through rollers, either dry or wet.
  • Machine Glaze (MG): Known as MG papers, these are paper that appear to have a glazed finish on one side and a rough finish on another. Process occurs on a Yankee dryer when wet paper comes into contact with a steam-heated, smooth roller. Pressure is applied by the roller to the paper.
  • Misregister: A problem in multiple color printing when the different color images do not line up properly as the successive colors are printed on the page.
  • Mixed Office Waste: Wastepaper generated from offices, such as letters, memos, invoices, etc. which are collected and sorted for paper qualities.
  • Moisture Resistance: The ability of a material to resist taking on moisture and breaking down when exposed to it.
  • Mullen Test: A test used to measure the bursting strength of paper. Also referred to as pop test.
  • Negative: A photographic image on film which reverses the black and white areas of the original. The black areas on the original are clear on the negative and the white areas of the original are black on the negative. The negative film is used in the platemaking process.
  • Negative Image: A reversed image where the image that is usually black on a white background is reversed to be white on a black background (Fig. 4).

Figure 4. Positive & negative images

  • Non-Image: Any area, on an art-board, negative or plate, that is not to have any printing.
  • Opacity: The amount of “show through” in a sheet from one side to the other. The higher the opacity the less likely that the printing on one side will be visible from the other side.
  • Out-of-Register: When an image is not printing in the exact location that it is supposed to. When printing more than one color, if the colors do not line up properly, they are out of register.
  • Pantone Matching System (PMS) ©: A registered name for an ink color matching system used to compare, match and identify specific colors (Fig. 5).

Figure 5. Pantone matching system

  • Paper Grade: The quality of paper as determined by the ingredients of the stock such as wood or cotton fiber and the method of manufacturing. All papers fit into a group or type of paper which is its grade.
  • Post-Consumer Waste: Waste paper that has passed through the end-user, such as newspapers, office papers, paper bags and cartons.
  • Post-Printed Bags: Any bag that is printed or hot stamped after the bag has been manufactured. Allows for small quantities to be printed with faster lead times.
  • Pre-Consumer Waste: Waste paper that has been disposed of during the converting process. This may consist of paper trim, die clippings from die cutting of envelopes and corrugated boxes, or waste off the printing press. This is waste that has not passed through the end user.
  • Pre-flight: A procedure used to be sure all digital files have been prepared properly before putting them into production. They are checked for correct type fonts, completeness, composition, and compatibility.
  • Proof: A copy of the artwork representing the finished product. It is used for review and approval.
  • Raster Image: Also called bitmap image, is a reproduced graphic (text or image) which is displayed on a video monitor as pixels or on paper as an array of dots. It is identified in terms of resolution, such as dots per inch or pixels per inch. Raster images are produced by scanners, digital cameras or software editing programs (Fig. 6).

Figure 6. Examples of raster or bitmap images

  • Raster Image File Format (RIFF): An expanded version of the TIFF file format used for graphics, which is used by many scanners.
  • Register: 1) Aligning the images of each color so that they are printed in the proper location on the paper. 2) Aligning one part of a form with the next so that all parts are aligned. All parts must be in register so that when the form is imprinted or filled out, the impression will transfer to the proper location on each part.
  • Release Liner (Peel & Seal): The backer material or carrier sheet of a pressure sensitive material. It protects the adhesive until time of use, generally has a release coating applied to allow the adhesive to release easily. Also referred to as the backing or liner (Fig. 7).

Figure 7. Release liner

  • Repeat Length: On a web press, it is the circumference of the impression cylinder.
  • Resolution: The measurement of output quality expressed in pixels (dots) per inch on a computer monitor or dots per inch on printed media. For example, a monitor displaying a resolution of 800 by 600 refers to a screen capable of displaying 800 pixels in each of 600 lines, which translates into a total of 480,000 pixels displayed on the screen. When referring to printed media, a 300 dpi (dots per inch) printer for example, is capable of outputting 300 dots in a one-inch line, which means that it has the ability of printing 90,000 distinct dots per square inch (300 x 300).
  • Reverse: To produce an image that is white on a solid background. When printing, the reverse area will be the color of the stock being printed on (Fig. 4).
  • Reverse Type: The background is printed instead of the type. The type will be the color of the stock being printed on (Fig. 8).

Figure 8. Reverse type

  • Rub-Off: 1) Ink on printed sheets, after sufficient drying, which smears or comes off on the fingers when handled. 2) Ink that comes off the cover during shipment and transfers to other covers or to the shipping carton or mailer. Also called Scuffing.
  • Sans Serif Type: A typeface without serifs, the cross strokes on the ends of the letters (Fig. 9).

Figure 9. Sans Serif type

  • Screen Printing: A printing method where a squeegee is used to force ink through a mesh fabric that has a stenciled image area that allows the ink to pass through the mesh to create the image (Fig. 10).

Figure 10.  Screen printing

  • Screen Tint: A screen pattern that consists of dots that are all the same size and create an even tone (Fig. 11).

Figure 11. Screen tint

  • Serif Type: A typeface that has the cross strokes on the ends of the letters (Fig. 12).

Figure 12. Serif type

  • Single Wall Bag: Manufactured from a single layer of paper.
  • SOS (Self Opening Style) Bag: Four bag sides and the bottom, with no handle, and a serrated-top edge. Generally known for use as lunch bags and grocery style bags in a variety of sizes.
  • Soy Based Ink: Inks whose pigment vehicles contain soybean oils instead of petroleum products. Soybean inks are a good alternative to petroleum base inks because of their ease of use and because of their environmental considerations. Soy based inks have a very limited role in flexographic printing. Offset lithographic inks are thick and pasty. The materials within which pigments are dispersed are petroleum based compounds. It is these thick, pasty compounds that soy oil is designed to replace in offset lithographic inks.
  • Substrate: The material or stock that serves as the base onto which another material, chemical or solution is applied. Materials such as paper, plastic, film and acetate can all be the base substrate that may have ink, adhesive, photosensitive emulsion or a laminated material applied to one or both sides.
  • Supercalendered: An additional papermaking process where the paper runs through a set of alternating steel and fiber covered rollers. Supercalendering produces a very smooth thin sheet (Fig. 13).

Figure 13. Comparison of papers in respect of calendering

  • Tack: The stickiness of ink required to adhere properly to the type of substrate being printed on. Too much tack can cause the fibers to be pulled off the paper causing picking.
  • Tagged Image File Format (TIFF): A graphics file format developed by Aldus, Adobe, and Apple that is especially suited for representing large bitmaps, such as scanned black and white or color images.
  • Tear Strength: Paper’s ability to resist tearing while going through various stages of production such as printing, folding, book binding and miscellaneous bindery operations.
  • Tensile Strength: The ability of the paper to withstand the stress and strain applied to it before breaking down and pulling apart.
  • Tint: 1) The addition of white to a color. 2) Also, when printing a color in any type of screening that causes the ink coverage to be less than 100%.
  • Trapping: The overlapping of adjoining colors or ink to help prevent the possibility of a fine white area showing between colors due to misregistration of color negatives or due to normal variations on the press (Fig. 14).

Figure 14. An example of trapping

  • I Turn-top Bag (folded top): A style of bag construction where the top of the bag is folded to the inside yielding a more finished look than the “saw tooth” style.
  • Uncalendered: Paper that has not been sent through the stack of polished steel rollers used in the calendering process which smooths the surface of the paper (Fig. 13).
  • Vector Graphics: Graphics and pictures represented by lines and curves rather than using dot or pixels as used on bitmapped or raster images. Vector graphics are infinitely scalable without loss of quality.
  • Virgin Paper: Paper manufactured from new pulp. Does not contain any recycled material.
  • Wet-Strength: Papers Once wet, ordinary papers lose most of their original dry-strength properties. Wet strength papers possess properties that resist disintegration and rupture when saturated with water. Papers are classified wet strength when they retain 15% or more of their dry-tensile strength. Superior quality wet strength papers may retain as much as 50%.

Glossary Of  Corrugated Boxes

  • Adhesive: Substance used to hold plies of solid fiberboard together; to hold linerboard to the tips of flutes of corrugated medium; or to hold overlapping flaps together to form the joint or to close a box.
  • Bale: A shaped unit of materials, enclosed in a fiberboard container or other wrapping, bound by strapping, rope, or wire.
  • Basis Weight: An attribute of containerboard, but the values may be determined from the combined corrugated board. When determining the basis weight from combined board, the take-up factor of the corrugated medium, which varies with flute size, and the weight of the adhesive must be considered.
  • Bending: Ability of containerboard or combined board to be folded along score lines without rupture of the surface fibers to the point of seriously weakening the structure.
  • Blank or Box Blank: A flat sheet of corrugated board that has been cut, scored, and slotted, but not yet glued together.
  • Box Manufacturer’s Certificate (BMC): In the United States, the Box Maker’s Certificate is printed in a round or rectangular design on a corrugated box flap that certifies the box conforms to all applicable standards. This stamp identifies the material and certifies the results of the Mullen Bursting Test or the Edge Crush Test. Sometimes referred to as a class stamp or cert stamp.
  • Box Style: Distinctive configuration of a box design, without regard to size. A name or number identifies styles in common use.
  • Boxboard: Types of paperboard used to manufacture folding cartons and set up (rigid) boxes.
  • Built-Up: Multiple layers of corrugated board glued together to form a pad of desired thickness, normally used for interior packing.
  • Bulk: Unpackaged goods within a shipping container. Also, a large box used to contain a volume of product (e.g., “bulk box”).
  • Bundle: Shipping unit of two or more boxes grouped together, usually with plastic banding.
  • Bursting Strength: Strength of material in pounds per square inch, as measured by the Mullen or Cady tester.
  • Caliper: Usually expressed in thousandths of an inch (mils) or sometimes referred to as “points.” Caliper measurements are also used as an indirect measure of manufacturing quality.
  • Cardboard: Thin, stiff pasteboard used in the creation of playing cards, signs, etc. Term is often misused to refer to Boxboard (folding cartons) and Containerboard (corrugated boxes).
  • Carton: Folding box made from Boxboard, used for consumer quantities of product. A carton is not recognized as a shipping container.
  • Case: Corrugated or solid fiberboard box as used by the packaging industry.
  • Chipboard: Paperboard generally made from recycled paper stock. Uses include backing sheets for padded writing paper, partitions within boxes, and the center ply or plies of solid fiberboard.
  • Combined Board: Fabricated sheet assembled from several components, such as corrugated or solid fiberboard.
  • Compression Strength: Corrugated box’s resistance to uniformly applied external forces. Top-to-bottom compression strength is related to the load a container may encounter when stacked. End-to-end or side-to-side compression may also be of interest for particular applications.
  • Containerboard: Paperboard components (linerboard, corrugating material and chipboard) used to manufacture corrugated and solid fiberboard. Raw materials used to make containerboard may be virgin cellulose fiber, recycled fiber or a combination of both.
  • Corrugated Board, Corrugated Fiberboard: Corrugated board is comprised of one or more layer of wavy corrugated medium (fluting) and one or more layer of flat corrugated linerboard.
  • Corrugator: Machine that unwinds two or more continuous sheets of containerboard from rolls, presses flutes into the sheet(s) of corrugating medium, applies adhesive to the tips of the flutes and affixes the sheet(s) of linerboard to form corrugated board. Continuous sheet of board may be slit to desired widths, cut off to desired lengths and scored in one direction.
  • Design Style: Style of fiberboard trays or caps having flaps scored, folded and secured at flange side walls forming the depth, as opposed to a slotted style having a set of major and minor closing flaps.
  • Die-Cut: Cut made with special steel rule dies. The act of making a part or container which is cut and scored to shape by such tools. Also, a box that is stamped out from a steel rule die, as opposed to being produced on a flexo folder gluer. Die-cut boxes provide greater design options and tighter size tolerances.
  • Dimensions: For regular slotted containers (RSC), box dimensions are expressed as length x width x height, always using inside dimensions.
  • Double Wall: Corrugated board construction where two layers of medium are glued between three layers of flat linerboard facing.
  • Edge Crush Test (ECT): The Edge Crush Test is a standard industry measure of the stacking strength, the amount of force in pounds per inch needed to cause compressive failure of an on-edge specimen of corrugated board. This measured force is a primary factor in predicting the compression strength of the completed box. When using certain specifications in the carrier classifications, minimum edge crush values must be certified.
  • Facings: Sheets of linerboard used as the flat outer members of combined corrugated board. Sometimes called inside and outside liners.
  • Fiberboard: General term describing combined paperboard (corrugated or solid) used to manufacture containers.
  • Flaps: Extension of the side wall panels that, when sealed, close the remaining openings of a box. Usually defined by one score line and three edges.
  • Flexo Folder Gluer: Machine, usually capable or running at high speed that prints, folds, cuts, and glues sheets of corrugated board, converting them into shipping boxes.
  • Flute: The wavy layer of corrugated medium that is glued between the flat inner and outer sheets of linerboard to create corrugated board. Fluting generally runs parallel to the height of a shipping box. Flute sizes come in A, B, C, D, E, and F.
  • Joint: The opposite edges of the blank glued, stapled, wire stitched, or taped together to form a box.
  • Kraft: German word meaning “strength”, designating pulp, paper, or paperboard produced from wood fibers.
  • Liner: Creased fiberboard sheet inserted as a sleeve in a container and covering all side walls. Used to provide extra stacking strength or cushioning.
  • Linerboard: Flat sheets of paper that comprise the outer surfaces of a sheet of corrugated board.
  • Medium: Paperboard used to make the fluted layer of corrugated board.
  • Mullen (or Burst) Test: The Mullen Test is a standard industry measure of the bursting strength of corrugated board to withstand external or internal forces, and to contain the contents during handling. This test certifies that the box can withstand the stated pressure (lbs. per sq. in.) as applied by a Mullen Tester.
  • Overlap: Design feature wherein the top and/or bottom flaps of a box do not butt, but extend one over the other. The amount of overlap is measured from flap edge to flap edge.
  • Pad: Corrugated or solid fiberboard sheet, or sheet of other authorized material, used for extra protection or for separating tiers or layers of articles when packed for shipment.
  • Palletizing: Securing and loading containers on pallets for shipment as a single unit load, typically for handling by mechanical equipment.
  • Panel: A “face” or “side” of a box.
  • Paperboard: One of the two major product categories of the paper industry, Containerboard and Boxboard. Includes the broad classification of materials made of cellulose fibers, primarily wood pulp and recycled paper stock, on board machines. (The other major product group of the paper industry is paper, including printing and writing papers, packaging papers, newsprint and tissue.)
  • Partition: Set of corrugated, solid fiberboard or chipboard pieces that interlock when assembled to form a number of cells into which articles may be placed for shipment.
  • Ply: Any of the several layers of linerboard or solid fiberboard.
  • Point: Term used to describe the thickness or caliper of paperboard, where one point equals one thousandth of an inch.
  • Puncture Resistance: Puncture resistance of combined board indicates the ability of the finished container to withstand external and internal point pressure forces and to protect the product during rough handling. This method is used on heavy double wall and triple wall as an alternative to burst.
  • Regular Slotted Container (RSC): Box style created from a single sheet of corrugated board. The sheet is scored and slotted to permit folding. Flaps extending from the side and end panels form the top and bottom of the box. The two outer flaps are one-half the container’s width in order to meet at the center of the box when folded. Flute direction may be perpendicular to the length of the sheet (usually for top-opening RSCs) or parallel to the length of the sheet (usually for end-opening RSCs).
  • Score or Score Line: Impression or crease in corrugated or solid fiberboard, made to position and facilitate folds.
  • Scored and Slotted Sheet: Sheet of corrugated fiberboard with one or more score lines, slots or slits. May be further defined as a box blank, a box part, a tray or wrap, a partition piece, or an inner packing piece.
  • Seam: Junction created by any free edge of a container flap or panel where it abuts or rests on another portion of the container and to which it may be fastened by tape, stitches or adhesive in the process of closing the container.
  • Set-Up Boxes: Boxes that have been squared, with one set of end flaps sealed, ready to be filled with product. An article that is packed for shipment in a fully assembled or erected form.
  • Sheet: Rectangle of combined board, untrimmed or trimmed, and sometimes scored across the corrugations when that operation is done on the corrugator. Also, a rectangle of any of the component layers of containerboard, or of paper or a web of paperboard as it is being unwound from the roll.
  • Slit: Cut made in a fiberboard sheet without removal of material.
  • Slit Score: Cut made in a fiberboard sheet through only a portion of the thickness in a box blank to allow its flaps and sides to be folded into a shipping box.
  • Slip Sheet: Flat sheet of material used as a base upon which goods and materials may be assembled, stored and transported.
  • Slot: Wide cut, or pair of closely spaced parallel cuts including removal of a narrow strip of material made in a fiberboard sheet, usually to form flaps and permit folding without bulges caused by the thickness of the material. Common widths are 1/4 in. (6 mm) and 3/8 in. (9 mm).
  • Stacking Strength: Maximum compressive load a container can bear over a given length of time, under given environmental/distribution conditions, without failing.
  • Tensile Strength: Indicates the containerboard’s resistance to breaking when it is pulled into or through equipment during the converting and printing processes.
  • Tube: Sheet of combined boards, scored and folded to a multi-sided form with open ends. May be an element of a box style or a unit of interior packing that provides protection and compression strength.
  • Unit: Large group of bundled or unbundled boxes, banded and/or stretch filmed together for shipment.
  • Unitized Load: Load of a number of articles or containers, bound together by means of tension strapping, plastic shrink or stretch films.
  • Web: Continuous sheet of paperboard or paper.
  • Wrap-Around Blank: A scored and slotted sheet of corrugated fiberboard that is formed into a box by folding it around its contents. The user makes both the flap and joint closures.