Glossary of Terms

Click on a Glossary Term below to expand and open the definition.

AGST Finish

All Glass Sprinkler Top Finish. A finish with a very small inside diameter which allows the contents to be sprinkled from the bottle instead of running freely


A chromatic (brown) color of glass or plastic containers. It is used principally to protect the contents of the container from exposure to light

Annealing (Glass)

A controlled temperature method of gradually cooling glass containers in ovens or lehrs to avoid the creation of stresses and strains within the glass due to natural or uneven cooling

Annealing (Plastic)

With particular reference to plastic articles, this term generally defines a heating process which is designed to relieve material stresses resulting from the molding or forming of the article

Antistatic Agent

A chemical substance that can be applied to the surface of a plastic article, or incorporated in the plastic from which the article is to be made. Its function is to render the surface of the plastic article less susceptible to accumulation of electrostatic charges which attract and hold fine dirt or dust

Applicator Cap

A closure designed to apply the contents of the container

Applied Color Lettering (ACL)

Colored lettering or design of ceramic materials which are fused onto bottles


Acceptable Quality Level. This is a term used to denote the degree of acceptance to which customers will work in evaluating a shipment of containers

Art Work (Sketch, Rough, Layout)

A preliminary drawing usually done with pencils, chalk, or markers which combines the needs of the customer with the ideas of the artist


A refined version of the art work which shows the placement of all copy and illustrations as close to the final printed version as possible (but without being ready to go to the printer)

Finish Art or Camera Ready Art

Art work prepared so that it may be reproduced in the final form. All typography is in place and illustrations supplied in a form best suited to the process involved


An apparatus for sterilizing, by superheated steam under pressure

Backing Liner

The compressible paper material usually pulp or newsboard, to which the facing liner is attached or adhered. This compressible material compensates for any irregularities on the sealing surface.


A metal wire formed into a semi-circle to serve as a container handle. The ends fit into the ears on a metal or plastic can


A trade name applied to a synthetic resin. Its uses are similar to those of hard rubber and celluloid

Bead (Closure)

Either a depressed or raised ring-like configuration in the top of the cap

Bead (Metal)

A rounded, concave or convex line around the surface of a container or its end; used to stiffen or improve its appearance. Also used to secure the collar in a can

Beaded Cap

A cap featuring a bead of some design in its panel or top surface

Blow Molding

A method of fabrication in which a parison (hollow tube) is placed between the two halves of a mold (cavity), and forced to assume the shape of that mold cavity by use of air pressure

Body (Metal)

The sidewall of a container. The portion of a container to which top and bottom ends are attached by double searing, soldering, friction fit, etc. A cylinder-shaped part of a can. Refers, however, to any shape

Body Dimension

The width, thickness, diameter, and height of a bottle including measurements, controlling contours or other physical dimensions

Buttress Thread

A type of threading in which the thread sides terminate abruptly; the threading gradually tapering down to the neck finish. Designed to withstand maximum force in one direction only. The cross section of the thread is triangular

Cap (See Also Closure)

Any form of device used to seal off the opening of the container, so as to prevent loss of its contents


(1) The amount of space inside a container provided for a given amount of product
(2) Also, the total amount of volume inside a container. The latter is more correctly called the overflow capacity


The depression in a mold made by casting, machining, hobbing or a combination of these methods; depending on the number of such depressions, molds are designated as a Single-Cavity or Multi-Cavity


The tamper-evident plastic neck band covering the container neck and closure skirt. It can be printed with a sales message

Cellulose Band (Celon)

A band made of hydrated cellulose film that is extruded in continuous tubing form. The cellulose tubing is then processed and printed in this form and cut into individual bands of predetermined lengths. When the Celon is applied to the finish of the container, it is allowed to air dry. During this air-drying period it shrinks to form a skin-tight film over the finish of the bottle


A depressed configuration in the top of the cap added for strength, stacking purposes, retainer for plastisol, etc. The sides are sloping or of a radius construction, and the depressed section is flat

Child-Resistant Closures (CRC)

There are several types that have been developed for products that constitute a hazard to small children. Basic principles of CRC’s are:
(1) Press-turn
(2) Squeeze turn
(3) Combination-lock and hidden tab


The expanded edge or rim of a barrel, pail or drum

Choked Neck

A narrow or constricted opening in the neck of a container


Component of a capping machine which holds the closure for application to the container

Closure (for Metal Cans)

The joint or deal which is made in attaching the cover to a can; as in double seaming


Any structure or device which is designed to close off the opening of a container and prevent loss of its contents (See also Cap)

Coating (Closure)

A layer of varnish, inks or other organic material which has been applied in fluid form and dried, united with or adhered to the surface of the material from which the closure will be made

Coating, Litho

Refers to a pigmented coating used in lithographic decorations as a ground or base coat for printing inks

Coating, Protective

A coating, pigmented or non-pigmented, used to provide a non-reactive barrier between the can plate and the product or the atmosphere


(1) Non process: coatings which are not required to withstand sterilization processes
(2) Process: coatings characterized by their ability to withstand the process necessary for the sterilization of the contents of the containers

Color Concentrate

A measured amount of dye or pigment incorporated into a predetermined amount of plastic. This pigmented or colored plastic is then mixed into larger quantities of plastic material to be used for molding. The concentrate is added to the bulk plastic in measured quantity in order to produce a precise, predetermined color of the finished articles to be molded

Compartment Can

A series of containers so fabricated and assembled that the bottom end of one acts as a closure for the container below


A flowed latex compound or ground cork particles adhered to, and used as a liner in a closure

Composite Can

A can having a fibre body composed of a composite of paper (label and liner could be aluminum, foil, plastic), and one or both ends made of metal

Cone Top

A tapered shape top, which has the general shape of a frustrum of a cone

Continuous Thread

A continuous spiral projecting glass, plastic or metal ridge on the finish of a container intended to mesh with the thread of a screw type closure


The light, tough bark of the cork oak tree used in compo for closure or its liner, or as a plug for a container


The deterioration of a metal by chemical or electrochemical reaction with its environment

Crown Cap

This is a crimped closure. Flutes are pressed into the flaring skirt of a shallow metal disk, which holds an inner disk of resilient lining material that forms the actual seal

Crown Finish

The unthreaded finish used on beer and beverage bottles intended to be sealed with a crown cap


The tubular structure formed at the open end of a metal closure to provide a smooth, strong edge and to facilitate automatic handling of the closure


The line where the halves of a blow mold come together; the knife edges of the molds squeeze together and weld the top and bottom of the hot parison (Also called Pinch-Off)


An indented of depressed design or lettering that is molded into an article so as to be below its main outside surface

Deep Screw Cap

A cap having a deeper skirt and generally a heavier thread than the 400 finish series


Weight per unit volume of a substance, expressed in grams per cubic centimeter, pounds per cubic fit, etc


Any tool or arrangement of tools designed to cut, shape or otherwise form materials to a desired configuration


Any change from the original color, often caused by overheating, light exposure, irradiation, or chemical attack


A closure which has a rounded top surface

Double Friction

The type of rings and plugs having two friction wall fits (Also see Doubletite)

Double Seamed End

The part of a can which is attached to the body of a double seamed can


A type of ring and plug closure having two circumferential contact surfaces obtained by a “U” section in the plug fitting into the “U” in the ring. Thus two walls on the plug contact two walls on the ring

Drop Test

Any test method in which the article being tested is dropped in a specified manner for a specified number of times or until the article falls from impact

Dropper Cap

A container closure that includes a dropper and rubber bulb attached

Drum, Closed Head

Refers to the drum-type steel container (5 gallon capacity or more) which is supplied to the customer with the top and bottom ends seamed to the body. Also called a tight-head drum.

Dry Coloring

A method commonly used by fabricators for coloring plastics by tumble-blending uncolored particles of the plastic material with selected dyes and pigments.

Ear (Glass)

The name given the integral finger grip between the shoulder and finish of a ½ gallon, gallon, or other glass jugs to facilitate holding the jug

Ears (Metal)

Parts soldered, bumped, or riveted to the side of a can into which a carrying ball is inserted. Also, wavy symmetrical projections formed in the course of deep drawing or spinning

Effective Thread Turns

The amount of thread (turns) in a closure that is actually in contact with the bottle thread, when the closure is fully tightened on the bottle neck (finish)

Electrostatic Treating

One method of surface treating. This method produces a molecular change on polyolefin surfaces by means of corona discharge induced by extremely high voltage. It changes the surface to render it receptive to adhesion of paints, ink, and other coatings


Creating a design on the closure surface by raising the letters through pressure or dyes


The compacting of a plastic material and the forcing of it through an orifice in more or less continuous fashion

“F” Style Can

A rectangular base, general-line can fitted with a screw cap reclosure. Made in several sizes of liquid measure. “F” style originated as a designation for the “Flit” style can

Facing Liner

The liner material that is attached or adhered to the backing liner and acts as a barrier to the chemical reaction of the product

Fill Point

The level to which a container must be filled to furnish a designated quantity of the contents


A cheap, inert substance added to a plastic to make it less costly. However, fillers may also improve physical properties, particularly hardness, stiffness, and impact strength. The particles are usually small, in contrast to those of reinforcements; but there is some overlap between the functions of the two


The glass surrounding the opening in a container. So called because, when hand blown, it was the last part formed. It is now formed first, but shaped to accommodate a specific type of closure. This term is also used in reference to plastic containers


Any additional or extended part of a container, such as a ball, handle, nozzle, flange plug, or of a closure such as a dropper, sprinkler, powder shaker, etc


Any parts other than ends necessary to complete the closure of a can

Flame Treating

A method of rendering inert thermoplastic objects receptive to inks, lacquers, paints, adhesives, etc, in which the object is bathed in an open flame to promote oxidation of the surface of the article

Flat Top

A cap or shell in which the top or panel is perfectly straight across its entire diameter, without a bead or design


A glass industry term used to describe clear glass

Floating Liner

A liner that is not adhered to the inside of the closure


A term used to describe the method of applying a partial liner with nozzle

Fluorescent Pigments

By absorbing unwanted wave-lengths of light and converting them into light of desired wave-lengths, these colors seem to possess an actual glow of their own

Friction Cap

A closure designed to be held on by friction upon application to a container, building up resistance to movement of closure

Friction Top Can

A can with a removable cover consisting of a plug which fits into the ring in the top end of the can, depending on friction fit to retain its position

G-Cap (G-450)

A 70 millimeter cap with a deep screw threaded skirt (450)


A separate ring of a suitable material placed between the sealing surface of the container lip and the closure to provide a seal


The shine or luster of the surface of a material


Various devices for carrying pails

Head Space

The space between the level of the contents in the neck of a container and the closure. It is intended to furnish room for expansion of product due to heat or other action after packing

Heat Seal

A process of uniting two or more surfaces by fusion of the surfaces under conditions of time, temperature and pressure

Heat Transfer Label

A label which has been first printed on paper or other material and then is transferred to the container surface by means of heat


The part of a container between the bottom-bearing surface and the side wall

Hot Stamping

A printing operation in which roll leaf is stamped with heated metal dies on to the face of the plastics. Ink compounds can also be used. By means of felt rolls, ink is applied to type or a printing plate and by means of heat pressure, the image is impressed into material, leaving the marking compound in the indentation

Impact Resistance

Relative susceptibility of plastics to fracture by shock

Injection Blow Molding

A blow molding process in which the parison to be blown is formed by injection molding

Injection Molding

A molding procedure whereby a heat-softened plastic material is forced from a cylinder into a relatively cool cavity which gives the article the desired shape

Injection Mold

A mold into which heated and softened material is introduced from an exterior heating cylinder

Inner Seal

An additional seal of moisture proof material applied to the top of the container prior to, or during the application of the closure


An integral part of a plastic container consisting of metal or other material which may be molded into position of pressed into the molding after the molding operation is completed

Interrupted Thread

The threads of the finish of glass containers that are not continuous, having gaps at seam areas to avoid scratching internal coatings on closures


The indentations or crimping near the top of a cap. It is used for holding the liner inside the cap or as a grip for removing. It also provides a non-skid surface during the threading operation

Label Panel

The plain portion of a decorated container set up for application of labels


A liquid coating used in the manufacture of metal containers or closures. It dries through evaporation during a baking operation


The long, heated oven through which glass containers move on a conveyor belt so that gradual cooling will properly anneal and remove stress from the glass


A special material inserted inside the cap to ensure the seal and prevent evaporation or leaking. It also protects the product from chemical reactions

Liner Backing

The material bonded to the back of the paper or foil liner to provide a cushion for sealing the contents of a container

Liner Disc

The blanked, circular liner from the appropriate liner material, either paper or plastic, for inserting into a closure

Linerless Closure

A closure, usually plastic, that contains no liner


The extreme outer edge of the top of a container intended to facilitate pouring


A printing process especially adapted to fine halftone color effects or smooth ink solids

Lug Cap

A closure with raised internal impressions (instead of threads) that inter-mesh with similar “bosses” on the finish of a container

Lug Pail Cover

A type of cover commonly used on open-end 5 gallon steel pails. The pail cover is lined with puff-type compound which seats on the top rim of the pail. The seal is effected by compression of the cover to the pail. The seal is maintained by clinching the lugs, which are an integral part of the cover, to the pail rim.

Minimum Wall

A term that designates the thickness of the wall (body) of a container. Usually specified as the minimum thickness allowable for the body of a container


(v) To shape glass or plastic containers or closures by heat and pressure
(n) The cavity or matrix into which the material is placed and from which it takes its form

Mold Number

The number by which mold equipment is identified. It is used as exact glass container identification in ordering containers to be manufactured or shipped

Mold Seam

A vertical line formed at the point of contact of the mold halves. The prominence of the line depends on the accuracy with which the mating mold halves are matched

Molding (Compression)

A process of shaping or forming thermosetting material in a mold through the use of heat and pressure

Molding (Injection)

A process of shaping or forming thermoplastic material in a mold by cooling the previously heated plastic

Multi-Cavity Mold

A mold with two or more mold impressions, i.e., a mold which produces more than one container per molding cycle

Narrow Mouth

The finish of a container, which is small in relation to the diameter of the body


The portion of a glass container in which the shoulder cross-sectional area decreases to join the finish

Neck Bead

A small protruding circle of glass on a container at the point where the neck meets the finish of the container

Neck Bead Ring (or band)

Protruding ring just above the neck ring parting line necessary in the manufacture of glass containers and specifically in transferring containers from blank to mold

Neck Ring (or neck insert)

The part of the mold equipment which forms the finish of the bottle


Designates those items which do not require threading action when applied to glass or plastic containers such as snap caps, sifter fitments, pour-out fitments, etc


Refers to the shape of a general-line container where the top and bottom ends are rectangular in shape with rounded corners. Also called an “F” style can

Offset Printing

A printing technique in which ink is applied to a printing plate; it is then “offset” on a cylindrical rubber roll (blanket), and, finally onto the object being printed


Descriptive of a material or substance which will not transmit light. Opposite of Transparent. Materials which are neither opaque nor transparent are sometimes described as semi-opaque, but are more properly classified as translucent

Open Stock

Glass containers in factory inventory available for shipment to customers

Open Top Can

A classification of rounded, hermetically sealed cans which have soldered side beams and compound lined-double seams. Products packed in these containers are usually heat processed. Also known as “sanitary can” or “packer’s can”

Overflow Capacity

The capacity of a container to the top of the finish or to the point of overflow


An additional closure usually of foil or aluminum, over the primary closure. If disturbed, it offers evidence-tampering


A flaring or tapered-body container equipped with a bail or handle. A variety of top closures are used

Parting Line

A mark on molding or casting where the halves of the mold meet in closing


(1) The passage or diffusion of a gas, vapor, liquid, or solid through a barrier without physically or chemically affecting is
(2) The rate of such passage


A thermosetting plastic compound used to manufacture molded closures

Phenolic Lining

Phenolic Lining
A synthetic phenolic resin baked on metal as a lining


A raised edge around the cavity in the mold which seals off the part and separates the excess material as the mold closes around the parison in the blow molding operation


Inorganic material of various hues added to coatings or varnishes in order to color them


The glass or plastic tube portion of a dropper closure


One of many high-polymeric substances, including both natural and synthetic products, but excluding the rubbers. At some stage in its manufacture, every plastic is capable of flowing, under heat and pressure, if necessary, into the desired final shape


A liquid mixture of resins and plasticizers, usually applied in a dipping operation, which is solidified with the application of heat


A fitment used for closing or reducing the opening in the finish of a container


A thermoplastic material composed of polymers of ethylene. It is normally a translucent, tough, flexible, waxy solid which is unaffected by water and by a large range of chemicals


A tough, flexible, light-weight thermoplastic material made from polymerized propylene gas


A more rigid thermoplastic material synthesized from benzene

Polyvinyl Chloride (PVC)

A flexible thermoplastic material composed of polymers of vinyl chloride; a colorless solid with outstanding resistance to water, alcohols, and concentrated acids and alkaline

Pourout Finish

A container finish with an undercut immediately below the top, to facilitate pouring without dripping. It is used principally for prescription and other drug and chemical containers

Pourout Fitment

A plastic component of a glass or metal package, designed to improve the dispensing action of liquid products. It snaps over the glass bead or slips inside the can neck, with a screw cap applied over the fitment

Prototype Mold

A simplified mold construction, often made from light metal casting alloy or from any epoxy resin, in order to obtain information for the final mold and/or part design


The contour of the bottom of a plastic container designed in such a manner as to allow an even bearing surface on the outside edge and prevent the bottom from rocking


A method used to trim and size finished plastic bottles. A special rotating cutting tool trims the sealing surface smooth and simultaneously reams (bores) the bottle opening to the desired size

Recessed Panel

A container design in which the flat area for labeling is indented or recessed. See also Label Panel


Any of a class of solid or semi-solid organic products of natural or synthetic origin. A term often used on place of “plastic”

Rigid PVC

Polyvinyl chloride or a polyvinyl chloride/acetate copolymer, characterized by a relatively high degree or hardness

Screen Printing (ACL)

A printing technique which involves the passage of printing medium such as ink through a web or fabric which has been stretched on a frame where a refined form of stencil has been applied

Sealing Surface

The lip portion of the finish which makes contact with the sealing gasket or liner and forms a seal


The portion of a glass container in which the maximum cross section or body area decreases to join the neck of the container

Side Seam

The seam joining the two edges of a blank to form a body

Sifter Fitment

A plastic component of a package designed to allow shaking out of dry products, as with table salt shaker

Size Coat

A type of coating applied to the metal plate to allow subsequent coating or lithography to adhere to the metal plate


A fitment used in conjunction with a tapered stopper

Slip Cover

A removable cover which fits over and around the open end of a can, depending on friction fit to retain it in position

Snap Cap

A polyethylene plastic cap designed to hold securely to a particular container finish, but which can be released with a finger

Spiral Can

A laminated fibre container formed by winding the material in piles around a cylinder at a diagonal, in a continuous operation

Sprout Cap

A closure designed to facilitate pouring the contents of a container

Stacker Cap

A closure designed specifically to nest with the bottom plate of another container to facilitate the stacking of filled containers on top of each other


A cork shaped plug used to seal some bottles

Storage Life

The period of time during which a liquid or other packaged product can be stored under specified temperature conditions and remain suitable for use

Straight Neck

This refers to the neck of a bottle. Some have tapered necks, some have bulb necks and some have straight necks

Straight Sided Can or Pail

A round can or pail that has the same top and bottom diameter. Even without the cover, it must be stacked on upon the other


A form of liner, usually of glassine, that is applied over and bonded to a waxed under-liner. When the cap is removed, this tacseal liner adheres to the glass lip as a security-type liner

Tapered Neck

The neck portion of a bottle, gradually increasing in size, from the top of the bottle to its shoulder

Tapered Nesting Pail

A flared or tapered body metal container formed with a nesting ring which allows one container to be stacked with another


A registered trademark of Dennison Mfg Co. for a decorating process for plastic. It transfers the image of a label or decoration to the object under the influence of heat and pressure


(a) Capable of being repeatedly softened by heat and hardened by cooling
(n) A material that will repeatedly soften when heated and harden when cooled. Typical of the thermoplastics family are the styrene polymers and copolymers, acrylics, cellulosics, polyethylenes, vinyls, nylons, and the various fluocarbon materials


A material which softens when subjected to heat and then undergoes a chemical reaction which prevents it from softening again under heat. Typical materials are in the phenolic family


The indented, curved, formed section of the cap on the skirt that engages and matches the thread of the glass for screw fit purposes

Thread Contact

The actual physical contact when the thread of the cap makes or engages the bottle thread finish, measured in degrees

Thread Contour

The shape or type of thread design as observed in a cross-section along the major axis, i.e., flat-headed, square, round etc

Tin Plate

A thin sheet of steel to which a specified weight of pure tin is applied by an electrolytic or hot-dip tinning process


The allowable variation from actual specifications permitted in manufacturing operation

Top Seal

A closure where the sealing surface is located on the top of the container finish


The amount of circular force applied to a container to seal or open it


Descriptive of a material or substance capable of transmitting some light, but not clear enough to be seen through


Descriptive of a material or substance capable of a high degree of light transmission (e.g., glass). Some polypropylene films and acrylic plastics are outstanding in this respect


Continental Can Co.’s trademark for its design of a ring and plug closure for round paint cans

Unit Mold

A simple mold which comprises only a single cavity without further mold devices. It is used for the production of sample containers having a shape which is difficult to blow