lacquer: A type of varnish that has many different formulations with some variations in characteristics. Materials that dry quickly by solvent evaporation. There are both natural and synthetic lacquers, both available transparent and pigmented.

lacquer thinner: A blend of solvents used to reduce viscosity of lacquer and/or to eliminate blushing.

laminate: The process of bonding together two layers of material with adhesive and heat/pressure.

laminated wood: An assembly made by bonding layers of veneer to a substructure with an adhesive.

landing: An intermediate platform in a staircase, part way between two floors of a building; a wide area halfway up a two part staircase.

lap marks: Marks left when a coat of finishing agent extends over an adjacent coat that has been allowed to dry too long so that the two coats do not blend and the edge of the second coat just sits on the top of the first coat.

leaf: An organ on a tree typically divided into a flattened portion and a narrow stalk, serving as the principle site of photosynthesis.

leveling: Ability of a film to flow out free from ripples, pock marks, orange peel, brush marks, runs, sags, or other surface defects after application.

leveling agent: Additive which is able to reduce the surface tension of a finishing agent to obtain better wetting and leveling effect, and to improve the surface flow of a finishing agent.

life: an expression of the period of time a film will retain elasticity or durability

lifting: Softening of a dried film by the solvents of a succeeding coat, which causes raising and wrinkling of the first coat.

light fastness: The ability to withstand color change on exposure to light.

lignin: The natural adhesive and bonding agents found in the cellular structure of wood. It is the cementing layer between wood cells and the second most abundant component of wood.

linear foot: Measurement based on length in feet of a product. A measure frequently used in selling wood planks and mouldings. It refers to a one foot long section, regardless of length and thickness, and is used in place of board foot pricing.

linseed oil: Aka flax seed oil- a clear to yellowish oil obtained from the dried ripe seeds of the flax plant. Used on its own as is or blended with other oils, resins, and solvents to create a wood finishing agent.

livering: Is when the coating becomes gel-like in the container.

log cabin corner: Also called lapped corner- a corner pattern in which ends of perpendicular boards overlap, the end of one butting up against the side of another.

loose knot: A knot that is not held firmly in place by growth and cannot be relied upon to remain in place when the board is put in service.

lumber: Solid wood in any form that has been reduced by cutting into a tree.

luster: Shine/polish/sheen/- the way in which something reflects light.