Lacquer

Solution of a substance in one or more organic solvents which, on evaporation of the solvent, leaves a more or less hard, transparent and glossy protective film, such as  shellac in alcohol.

Lagoon

Large, more or less shallow, enclosed area or basin, into which impure water, or waste liquor is introduced for storage, mixing, settling-out of solids, etc.

Lake

Insoluble organic pigment made from a dye and a mordant. It is obtained by precipitating a soluble organic dye with a precipitating agent, such as a metallic salt.

Lambskin

1. A lamb’s skin or a small fine grade sheepskin, or the leather made from either.

2. Such a skin dressed with the wool on and used especially for winter clothing.

Laminate (v); laminating

Ready prepared finish film on a carrier foil which is applied to the leather surface by pressure and heat. After plating the carrier foil is peeled off.

Laminated leather

Composite material normally composed of layers of leather laminated together. If a layer of another material is incorporated the term is defined differently.

See: Patent laminated leather; plastic surface laminated leather.

Landfill

Area where waste and rubbish are deposited and eventually buried.

Landfill (sanitary)

A specially engineered site for disposing of solid waste on land, constructed so that it will reduce hazard to public health and safety as well as the environment. Some features include an impermeable lower layer to block the movement of leachate into ground water, a leachate collection system, a system permitting the control of methane, and daily covering of garbage with soil.

Lanolin

Purified wool grease that has been refined to produce a paler colour and reduce its odour and free fatty acid content. Lanolin is often used in cosmetics and in ointments.

Larrigan leather

Oil-tanned hide leather, used largely for moccasins.

Note: North American term.

Lastometer

Apparatus used to give information about the tendency of a material to cracking or breaking during the lasting process in shoe manufacture.

Latigo leather

Cattle hide leather tanned with a combination of alum and gambier, used for cinches, ties, saddle strings and other saddlery work and for army accoutrements.

Note: North American term.

Layer

Coat formed by one application of a season or finish.

LC

See: Lethal concentration.

LC50

Concentration of a substance in the environment, such as a river or in the atmosphere, which causes the death of a specific species, such as fish.

LC50 indicates a substance which kills 50% of a group of specific animals. It is generally expressed in mg of substance/l, but also mg of substance/cm² when a substance or preparation is directly tested on the skin.

See: Lethal concentration.

LCA

See: Life cycle assessment.

LCCP

See: Long-chained chlorinated paraffins.

LCSCP

See: Long-chained sulphochlorinated paraffins.

LD

See: Lethal dose.

Leach (v); leaching

Removal of desired soluble constituents from a material by a suitable solvent, such as tannins, etc., from vegetable tanning materials by water.

Leachate

Liquid that has percolated through solid waste and/or has been generated by solid waste decomposition, and has dissolved or suspended materials in it. The liquid may contaminate ground or surface water.

Leaf tannin

Tannin contained in leaves, such as  sumac tannin.

Leather

General term for hide or skin with its original fibrous structure more or less intact, tanned to be imputrescible. The hair or wool may or may not have been removed. Leather is also made from hide or skin which has been split into layers or segmented either before or after tanning. However, if the tanned hide or skin is disintegrated mechanically and/or chemically into fibrous particles, small pieces or powder and then, with or without the combination of a binding agent, is made into sheets or other forms, such sheets or forms are not leather. If the leather has a surface coating, this surface layer, however applied, must not be thicker than 0,15 mm.

Leather goods

General term used for goods made from leather.

Note: Bags, pocket books, belts, cases, etc.

Leather stacker

Device for receiving leather automatically and individually from a machine or conveyor and laying them flat on each other, for example, on a pallet.

Leatherboard

More or less thick and flexible sheet material, composed mainly, if not entirely, of ground or disintegrated leather, held together with a suitable binder, such as rubber latex. Leatherboard is not leather.

If tanned hide or skin is disintegrated mechanically and/or chemically into fibrous particles, small pieces or powder and then, with or without the combination of a binding agent, is made into sheets or other forms, such sheets or forms are not leather.

Leatherboard is sometimes, mistakenly, referred to as “bonded” or “composition” leather, but none of these are leather.

See: Leather; tannage.

Lecithin

Member of a type of phospholipid present in the skin, and also in egg-yolk, composed of glycerol esterified with two molecules of higher fatty acid and one molecule of phosphoric acid, linked to a molecule of a nitrogenous base, choline.

Leopard grain

Grain defect on sheepskin leather visible as slightly rough, dull spots, scattered over the surface, similar to the spots on a leopard skin. The grain is actually damaged on the raised areas of the mottle.

Lethal concentration (LC)

Concentration of a substance in the environment, such as a river or in the  atmosphere, which causes the death of a specific species.

Lethal dose (LD)

Dose of a substance which causes the death of a specific species. It is generally expressed in mg of substance per kg of the animal.

Leuco-compound

Compound related in constitution to a dye, into which it can be converted by oxidation or reduction. This product could be colourless, or almost colourless.

Levacast

Finish used for upgrading splits. A natural leather grain structure is taken from leather by making a rubber sheet-like silicone matrix. By means of a special coating machine and a special finish preparation the grain structure on the matrix is transferred on to the surface of the finish coat, leaving a split leather which looks like a grain leather.

Levant

Leather with a characteristic drawn-grain pattern, produced originally by an astringent tannage, but nowadays by hand or machine boarding on vegetable or semi-chrome goat and sheepskin, or vegetable tanned seal skin.

Note: When the pattern is produced by embossing, it is called "Levant grain".

Level (v); levelling

Converting tanned hides or skins to a similar and uniform predetermined thickness over their area by operations such as splitting, shaving, whitening and buffing.

 See: Equalise; equalising.

Levelling agent

Material added before, or during dyeing which, by slowing down dye uptake, promotes the production of a level colour.

Levelling properties

Substance with the property to produce a level, even, or uniform distribution throughout a material.

Levelness

Even property. Note: Dyeing levelness.

Lice

Two types of lice cause damage to hides and skin. Biting and sucking lice can both cause subsequent  rubbing and scratching leading to abrasions and then infection. Also linked specifically to light spot, fleck and scatter or spread cockle damage.

Life cycle assessment (LCA)

Et  Technique for assessing the environmental aspects and potential impacts associated with a product by compiling an inventory of relevant inputs and outputs of a product system, evaluating the potential environmental impacts associated with those inputs and outputs, interpreting the results of the inventory analysis and impacts assessment phases in relation to the objectives of the study.

Lifting leather

Leather for the layers (lifts) used to build up heels.

Light spot

Small areas of grain loss caused by ectoparasite infestation. Fleck in suedes is generally caused by blood vessels that do not dye properly. See: Fleck.

Lighten (v); lightening

Alter or treat the colour of a dyed material in the direction of white, prior to dyeing.

Lightfast

Ability to endure long exposure to normal light conditions without serious deterioration of properties, especially colour.

Lime

Liquor based upon lime, calcium hydroxide, Ca(OH)₂ but usually containing other chemicals, such as sodium sulphide (Na₂S) or sodium hydrosulphide (NaHS), into which hides and skins are placed to loosen the hair, remove non-structural proteins, saponify fatty matter, open-up the fibre structure, etc.

Lime (v); liming

Treatment of hides and skin, originally essentially with a lime solution, but today also with other alkalis, or alkalis together with reducing agents, in order to loosen, or destroy, the hair or wool, remove unwanted proteins, saponify fatty matter, open-up fibre structure, etc.

Lime blast

Surface of a limed skin affected by lime blast appears shiny. Lime blast interferes with vegetable tanning and also affects dyeing adversely. It is caused by limed material being exposed to air for too long; the calcium hydroxide reacts with carbon dioxide in the air and forms calcium carbonate. High calcium levels in water can also cause lime blast.

Lime flesh (v); lime fleshing

Flesh hides or skins directly after liming.

Lime fleshings

Pieces of connective and adipose tissues cut from the inner surface of hides and skins in the fleshing operation (after liming).

Lime liquor

Liquor based upon lime, but usually containing other chemicals, into which hides and skins are placed to loosen the hair, remove non-structural proteins, saponify fatty matter, open-up the fibre structure, etc.

Note: Other chemicals include sodium sulphide.

Lime paint

Paste of lime applied to, or painted onto, the flesh sides of hides or skins to loosen the hair or wool.

Lime slurry

Lime residue similar to a sludge, composed of deteriorated hairs, dissolved proteins in suspension and unused lime.

Lime splits and trimmings

Waste obtained by splitting and trimming unhaired and limed hide or skin.

Lime sulphide

Lime liquor sharpened with a sulphide, usually sodium sulphide.

Lime water

Saturated solution of lime, that is at 1,6 g/l of Ca(OH)₂.

Limed weight

Hide weight after soaking, swelling in lime, minus hair, epidermis and after the removal of flesh by the fleshing machine.

Limed wool

Wool which has been removed from sheepskins after loosening by steeping the skins, folded wool inside, in a lime liquor.

Lime-sulphide unhairing

Removal of hair or wool from hides or skins by means of lime and sulphide.

Lime-yard

Department of the tannery where hides and skins are prepared for tanning and especially the section where they are treated with lime liquors to loosen the hair, to open-up the fibre structure, etc.

Liming pit

Pit in which hides or skins are steeped in milk of lime, or milk of lime together with other chemicals, to loosen the hair, remove unwanted protein constituents, open-up the structure, etc.

Note: Other chemicals usually include sodium sulphide.

Lining leather

Leather used for the linings of shoe uppers, handbags and other leather goods.

Lining shearling

Tanned and dressed sheep or lambskin, bearing short wool, used for lining purposes.

See: Shearling.

Lipase

Fat-splitting enzyme.

Lipid

Collective term for animal and vegetable oils, fats and waxes and certain related substances which are insoluble in water but soluble in fat solvents. Divided into simple, compound and, sometimes, derived lipids.

Lipolysis

Hydrolysis of triglycerides.

Lipoprotein

Group of widely distributed conjugated proteins that contain a considerable percentage of lipid (fat), such as lipid protein complexes. They occur in both soluble complexes, as in egg yolk and mammalian blood plasma, and insoluble ones, as in cell membranes.

Liquor loading

Loading of vegetable-tanned sole leather by drumming it in the wet state in a short float of concentrated tan liquor.

Liricure

Low salt short-preservation method based on direct application of powder preservative extender mixtures to the flesh surface of the hides or skins, the modus operandi closely resembling salt curing.

Live weight

Weight of live animal as it is presented to the auction house for sale.

Long-chained chlorinated paraffins (LCCP)

Paraffin (organic hydrocarbonate substance) with the formula R-Cl, where R groups represents a long-chain alkyl radical containing more than 20 carbon atoms.

Long-chained sulphochlorinated paraffins (LCSCP)

Paraffin (organic hydrocarbonate substance) with the formula R-SO₂-Cl, where R groups represents a long-chain alkyl radical containing more than 20 carbon atoms.

Loose and pipey grain

Grain layer which is loosely attached to the underlying main corium layer and forms folds or wrinkles when the leather is bent grain inwards. Often caused by staleness and can also be caused by mechanical processes. Note: Staking.

Losing colour

Alter in shade or intensity of colour, by the action of light, sun or weather.

Low grain

Grain enamel that has been damaged by bacterial, mechanical or chemical action. See: Rubbed/sueded/abraded grain.

Lubricant

Anti-friction agent, usually oil or grease, which lubricates a material or machine.

Lubricate (v); lubricating

Apply an anti-friction agent (a film of fluid, usually an oil, or of a semi-solid, such as grease) to a material surface such as leather fibres.

Lubricating power

Capability of fatty substance, solution or liquid, to enter into a porous solid such as leather in order to provide anti-friction properties to a material.

Lustre

Special top coating agent used for suede and nubuck leather to impart a sheen or lustre to the surface fibres.

Lymph

Colourless, aqueous fluid in the intercellular spaces of tissues and in the lymph tubes, containing a small amount of protein and certain cells (lymphocytes).

Lyotropic swelling,

Uptake of water by, and swelling of, a protein, produced by neutral salts and due mainly to the interaction of ions and molecules with non-ionic bonds, probably crosslinks of the hydrogen bond type, leading to lessened cohesion.

Lyotropic unhairing

Removal of hair or wool from hides or skins by the means of substances breaking hydrogen bonds.