Skis: how they are built, and how each discipline defines them.

This page describes skis as the trade press, the rule books and two collections describe them. It does not rate skis or say which suits anyone, and it covers no tuning, waxing or mounting procedure. Snowboards are on snowboards.

Construction terms

These descriptions come from a November 2025 article in Backcountry Magazine (Liam McGee, "Tech Talk: Ski Construction"). They are the publication's explanations, not a standard.

Core

The inner layer, which largely sets a ski's weight, strength, flex, damping and energy return. The article says most skis pair a main wood core with reinforcements, and that the layers are bonded with epoxy in what is called the layup. It adds that two skis made of the same materials can behave very differently because their layups differ.

Cap construction

The topsheet wraps down over the edges of the ski. The article says this saves weight but gives up some edge hold.

Sandwich construction

Vertical sidewalls of durable plastic or a bio-based material, which add weight and stiffness. A partial sandwich runs sidewalls underfoot and changes to a cap at the tip and tail.

Titanal

An aluminium alloy, described as a heavy metal layer, used for damping and stiffness. The article calls it common in resort and freeride skis, often as a mounting plate under the binding.

Carbon fibre and fibreglass

Carbon fibre is described as very stiff and light, with less forgiveness than wood. Fibreglass is described as strong and responsive, lighter than titanal and heavier than wood.

Camber and rocker

Camber is the arch underfoot that lets the ski flex. Rocker is an upturned tip and tail, which the article says helps a ski float in powder and feel more forgiving, while shortening the effective edge, meaning the length of edge actually in contact with the snow.

Freeskier magazine's construction glossary (half-cap construction, ABS and P-Tex sidewalls, and poplar, karuba, beech and maple cores) was seen only as a search-result summary because the page could not be opened, so its wording is unconfirmed.

How the rule books define the shape words

FIS uses a few measurements in its alpine racing rules, and its Specifications for Alpine Competition Equipment, Edition 2026/2027 (July 2026), define them by reference to ISO 6289, "Skis: Vocabulary":

• Sidecut radius: an approximation of the average radius of the ski's side outline.
• Waist width: the narrowest width of the running surface in the middle section.
• Shoulder width: the widest point of the shovel.

The same document describes racing-ski edges as made mainly of a hard, wear-resistant material that transmits lateral force, and sets no limit on the materials of the core, torsion box, edges, base or top sheet. ISO's catalogue shows the 2003 edition of ISO 6289 as withdrawn and points to a new 2025 edition; that 2025 edition was seen only as a pointer in a search listing and is unconfirmed. ISO also lists ISO 8783:2015, guidelines for conducting slope performance tests of alpine skis. Both come from catalogue entries seen in search results, because the iso.org pages could not be opened.

Ski types, discipline by discipline

Each discipline's governing document defines its own skis. They are separate sports with separate rules, so the definitions below are not interchangeable.

Touring and telemark gear is defined mainly through boot and binding standards. ISO 13992 covers alpine touring bindings and ISO 9523 covers rigid touring boots; ISO's catalogue entry for ISO 9523:2023 says it excludes softer-shelled boots such as telemark boots. Those standards are on bindings and standards and boots and sole norms. The research for this site did not read FIS's telemark equipment rules, so none are given.

The laminated metal ski

Te Papa, the Museum of New Zealand, records that the American aircraft engineer Howard Head developed the first laminated metal ski in 1947, founded the Head Ski Company in 1950, and that by 1960 Head skis and their competitors and imitators had replaced at least half of the world's wooden skis. The Aspen Times (28 March 2017) reported that the design took three years and 40 failed attempts, that the version that worked was tested in spring 1950, and that Head entered the National Inventors Hall of Fame in 2017.

The two sources differ on two points, and this page gives both:

• The date: Te Papa dates the first laminated metal ski to 1947. The Aspen Times describes development from about 1946, with the successful design tested in 1950.
• The construction: Te Papa describes its circa-1962 Head ski as a plywood core glued under heat and pressure between aluminium sheets, with plastic sidewalls and soles and continuous steel edges set into a slot in the aluminium sole plate, which the museum says was stronger than the earlier segmented edges. The Aspen Times describes two aluminium layers with plywood sidewalls around a plastic honeycomb core. The two may describe different stages of the design, but that is not confirmed.

Earlier ski history is on the oldest skis.

What this page leaves out

Makers' descriptions of individual models, seen only through retail listings, are not used. This site gives no advice on ski length, flex or width for any skier.