Glass packaging glossary
30 terms buyers meet in glass bottle quotes and drawings, defined in plain English.
- Acid frosting
- A finishing process that roughens the glass surface chemically with a hydrofluoric-acid-based solution, producing a fine, uniform, silky matte look. Because the texture is part of the glass, it does not peel. Spray frosting is a cheaper coating that imitates the look but is usually less durable and slightly coarser.
Related: Screen printing, Embossing - Amber glass
- Brown-tinted glass colored mainly by iron and sulfur compounds melted under reducing conditions. Amber blocks most ultraviolet and much short-wavelength visible light, so it is widely used for beer, olive oil, pharmaceuticals, supplements and essential oils that degrade under light. It generally gives stronger light protection than green or clear glass.
Related: Flint glass, Marasca - Annealing
- The controlled reheating and slow cooling of newly formed glass containers in a tunnel oven called a lehr. Forming leaves internal stresses because the inner and outer surfaces cool at different rates. Annealing relieves these stresses so bottles resist breakage. Poorly annealed glass, especially thick bases, can crack under thermal or mechanical shock.
Related: IS machine, Gob - Bar-top
- A bottle finish with a smooth bore designed for a T-shaped stopper, combining a synthetic or natural cork shank with a head made of wood, acrylic, glass, metal or zinc alloy. Common shank diameters include 19.5 mm and 21.5 mm. The shank must be slightly larger than the bore so it compresses and seals.
Related: Finish (neck finish), Crown finish, Swing-top - Boston round
- A cylindrical bottle with rounded shoulders and a short neck, usually with a GPI screw thread such as 20-400 or 24-400. It is widely used for essential oils, tinctures, pharmaceuticals, sauces and laboratory products, often in amber glass. The simple shape accepts droppers, pumps and screw caps.
Related: GPI thread, Amber glass, Dorica - CIF
- Cost, Insurance and Freight, an Incoterms rule for sea freight. The seller pays export clearance, ocean freight and minimum cargo insurance to the named destination port. Risk still passes to the buyer when goods are loaded on the vessel at origin. Buyers often add their own insurance because the default coverage is limited.
Related: FOB, 40' HQ - Crown finish
- A bottle neck designed for a crown cap, the crimped steel closure with a liner used on beer and soft drinks. The 26 mm crown is the common international size. Pry-off and twist-off crown finishes differ, so the cap and neck must be specified together. Crowning requires a crowner, either manual or automatic.
Related: Finish (neck finish), Swing-top - Decal
- Printed artwork on transfer paper that is applied to a bottle and then fired or cured. Ceramic decals fuse into the glass surface when fired, while organic decals cure at lower temperatures. Decals reproduce fine detail, many colors and gradients that are difficult with screen printing, making them suitable for complex illustrations and small text.
Related: Screen printing, Hot stamping - Dorica
- A round olive oil and vinegar bottle shape with a gently sloping shoulder and a classic Mediterranean appearance. It suits wraparound labels and is made in standard sizes, often in dark green or flint glass. Compared with the square Marasca, it packs less densely but is easier to label all around.
Related: Marasca, Boston round - Embossing
- Raised lettering, logos or patterns formed in the glass by engraving the mold; the recessed version is debossing. Because the design is part of the glass, it is permanent and adds no per-piece cost once the mold exists. It requires mold investment, sampling time and usually higher order quantities.
Related: Acid frosting, IS machine, MOQ - Extra flint
- A premium clear glass grade, sometimes called ultra flint or crystal white, with very low iron content and near water-white clarity. It is used for luxury spirits, perfume and heavy-base decanters where any tint would show. Definitions vary between suppliers, so buyers should agree on a reference sample rather than rely on the name alone.
Related: Super flint, Flint glass - Finish (neck finish)
- The top part of a bottle or jar that receives the closure, including the sealing surface, thread or bead, and any transfer ring. It is defined by a drawing with key dimensions such as thread diameter, root diameter, height and bore. The finish determines which caps, corks or crowns fit, so closures must be matched to it.
Related: GPI thread, ROPP, Crown finish, Bar-top, Lug cap - Flint glass
- The container-glass industry's name for clear, colorless soda-lime glass. It is made from silica sand, soda ash, limestone and recycled glass. Standard flint contains a small amount of iron oxide, which can give a faint green or blue tint in thick sections such as heavy bases. Flint offers little protection against ultraviolet light.
Related: Super flint, Extra flint, Amber glass - FOB
- Free On Board, an Incoterms rule for sea freight. The seller clears goods for export and loads them on the vessel at the named port of shipment. Risk passes to the buyer once the goods are on board, and the buyer pays ocean freight, insurance, import clearance and delivery. It is a common term for buyers importing from China.
Related: CIF, 40' HQ, MOQ - Gob
- A measured portion of molten glass cut by shears from the stream leaving the furnace feeder. Each gob drops into a blank mold on the IS machine and becomes one container. Gob weight determines the bottle's glass weight, and consistent gob shape and temperature are essential for even wall thickness and accurate capacity.
Related: IS machine, Annealing - GPI thread
- A standardized thread finish system from the Glass Packaging Institute, written as two numbers such as 28-400. The first number is the nominal thread outside diameter in millimeters; the second is the thread style. The 400 style has about one turn, 410 about one and a half, and 415 about two. Some listings reverse the order.
Related: Finish (neck finish), PE liner, TPE liner - Hot stamping
- A decoration process that transfers metallic or colored foil onto glass or a coated surface using a heated die and pressure. It produces sharp gold, silver and other metallic logos and accents. It works best on flat or gently curved areas and is often combined with screen printing or spray coating.
Related: Screen printing, Decal - 40' HQ
- A 40-foot high-cube shipping container, about 12.0 m long, 2.35 m wide and 2.69 m high inside, with roughly 76 cubic meters of space. It is about 30 cm taller than a standard container, allowing taller pallets. It is the usual choice for glass bottles, which fill space before reaching the weight limit.
Related: FOB, CIF, MOQ - IS machine
- The individual section machine, the standard equipment for forming glass bottles and jars. It has several independent sections, each forming containers from gobs of molten glass by blow-and-blow (common for narrow-neck bottles) or press-and-blow (common for jars and lightweight bottles). Changing mold sets causes downtime, which is one reason glass has minimum order quantities.
Related: Gob, Annealing, MOQ - Lug cap
- A metal closure with inward-facing lugs that engage short thread segments on the jar finish, so it opens and closes with a partial turn. Lug caps usually have a plastisol sealing compound and are common for jams, sauces and pickles, including hot-fill and vacuum-sealed products. Sizes are named by diameter, such as 63 or 82 mm.
Related: Mason jar, Finish (neck finish) - Marasca
- A traditional olive oil bottle shape with a square cross-section, tall body, short shoulder and long neck. It packs efficiently on shelves and in cartons and gives flat panels for labels. Marasca bottles are commonly made in dark green, amber or flint glass in sizes from about 100 to 1,000 ml, often with 31.5×24 mm finishes.
Related: Dorica, Amber glass, ROPP - Mason jar
- A wide-mouth glass jar with a continuous screw thread, originally designed for home canning. Traditional versions use a two-piece closure of a flat lid with sealing compound and a separate screw band. Today the term also describes decorative and storage jars for food, drinks and candles.
Related: Lug cap, Finish (neck finish) - MOQ
- Minimum order quantity: the smallest quantity a supplier will produce or sell for an item. In glass, MOQs reflect continuous furnace operation, machine changeover costs and color campaigns. Stock bottles have lower MOQs, custom molds higher ones, and decoration adds its own per-design minimums. MOQs vary by supplier, item and season.
Related: IS machine, Embossing, FOB - PE liner
- A polyethylene disc or foam insert, such as EPE foam, fitted inside a screw cap to seal against the bottle's sealing surface. PE liners are inexpensive and widely used for beverages, spirits and dry goods. Compatibility with the product and the required seal quality should be tested, especially for oils, high-alcohol or oxygen-sensitive contents.
Related: TPE liner, GPI thread - Pilfer-proof
- A closure feature that shows whether a container has been opened, also called tamper-evident. On aluminum ROPP and many screw caps, a perforated band separates from the cap on first opening and stays on the neck. Pilfer-proof closures protect consumers and brands and are expected on many spirits, oils and beverages.
Related: ROPP, Lug cap - ROPP
- Roll-on pilfer-proof: an aluminum closure supplied as a plain unthreaded shell. On the capping machine, rollers form the thread against the glass and tuck a perforated band under the neck bead. The band breaks on first opening, showing tampering. Common sizes include 28 mm for spirits and 31.5×24 mm for olive oil.
Related: Pilfer-proof, Finish (neck finish), Marasca - Screen printing
- A decoration method that pushes ink through a mesh screen onto a rotating bottle, one screen and pass per color. Ceramic enamel inks are fired at high temperature and become very durable. Organic inks cure by UV or low heat and offer brighter colors with lower abrasion resistance. Setup costs make per-design MOQs common.
Related: Decal, Hot stamping, Acid frosting - Super flint
- A higher grade of clear glass with lower iron oxide content than standard flint, giving a whiter, more brilliant appearance. It requires purer raw materials and limits the use of mixed cullet, so it costs more. It is common for premium spirits, fragrance and reed diffuser bottles. Grade names are commercial, so compare physical samples.
Related: Flint glass, Extra flint - Swing-top
- A resealable bottle closure using a wire bail attached to the neck, a ceramic or plastic stopper, and a rubber gasket. Pressing the lever compresses the gasket onto the bottle mouth. Swing-tops are used for craft beer, lemonade, oils and gift bottles, and need a neck designed for the wire fitting.
Related: Bar-top, Crown finish, Finish (neck finish) - TPE liner
- A liner made of thermoplastic elastomer, a rubber-like material that compresses to form a seal inside a closure. TPE liners give good resilience and sealing on minor surface variations and are used in screw caps for spirits, wine and beverages. Suitability depends on the product, so test with the actual contents.
Related: PE liner, GPI thread, ROPP