A flexible substitute for shell, horn, and corozo

Polyester buttons are made from unsaturated polyester resin, a petroleum-derived material. The resin is liquid and cures at room temperature, which makes it easy to process. Because of its thermosetting properties, polyester has long been widely used for apparel buttons.

In 1955, a manufacturing technique was developed in the United States that used polyester resin to reproduce the glossy luster of shell. This innovation quickly replaced acrylic, which had been the mainstream material up to that point, and polyester buttons spread to Japan as a substitute for shell buttons. Today, polyester accounts for a large share of button production not only in Japan but worldwide.

Because polyester’s colour can be freely adjusted, it can be used to imitate buffalo horn, shell, corozo nut, and many other materials. This flexibility allows for a wide range of designs. Manufacturing methods vary depending on the material being reproduced: one common technique is to pour resin into aluminum pipes to create patterned rods for button blanks, while another is to pour it into large drums over a meter in diameter, where centrifugal force forms layered sheets. In addition to single-material designs, polyester is also often combined with other materials such as metal, acrylic, or shell to create buttons with even greater variety and appeal.

A strong and versatile plastic, ideal for metal-plated buttons

ABS plastic is a copolymer made from three components: acrylonitrile (A), butadiene (B), and styrene (S). It combines the key characteristics of each — heat resistance, rigidity, oil resistance, and weather resistance from acrylonitrile; elasticity from butadiene; and gloss, electrical properties, mouldability, and impact resistance from styrene.

Thanks to these properties, ABS is regarded as the best material for metal-plated plastic buttons. It is highly processable and can be worked using a variety of methods, but for buttons, the injection moulding process is commonly used for efficient mass production.

Since the 1970s in Japan, ABS has become widely used as a substitute for metal buttons. Alongside single-material designs, many ABS buttons are also combined with other materials, resulting in a wide variety of styles and applications.

Timeless buttons with a lasting shine

The main materials used for metal buttons today are brass and zinc, offering a wide variety of finishes and colors through plating.

Brass buttons are often seen on school uniforms or navy blazers. Because brass is highly malleable, it can be smoothly processed with techniques such as pressing, embossing, or cutting. Most brass buttons are of the two-part hollow type, made by joining a front and back piece together — a distinctive feature of brass button construction.

Zinc, on the other hand, allows for even more detailed relief work. Zinc alloy buttons are typically made by die casting, in which molten metal is poured into a metal mold. For especially complex motifs there are methods such as rubber casting, where molten metal is poured into a rubber mold created from a master model, making it possible to reproduce intricate designs and enable mass production.

Metal buttons are widely used for uniforms and branded apparel worldwide.

Lightweight buttons with flexible design options

Nylon began attracting attention as a new material for buttons around 1960. It is made from polyamide resin, a petroleum-based material, and is usually processed by injection molding, where molten resin is poured into a mold to form the shape. This method also allows nylon to be combined with other materials — for example, metal parts can be molded in at the same time without adhesives, meeting the demand for combination buttons.

One of nylon’s greatest strengths is the wide range of surface treatments it supports. Fine fabric weaves, leather-like textures, engraved motifs or lettering, and many other designs can be reproduced. The material itself is also available in a wide range of variations such as transparent or pearlescent finishes.

Nylon buttons are well-suited to mass production, being lightweight and highly dyeable.

Rooted in Italian craftsmanship

Urea is a unique material that makes it possible to reproduce the refined look of natural materials such as horn and nut in high-strength resin. It is processed in a distinctive way, developed to bring out natural colours and patterns in buttons and buckles.

At IRIS, we introduced advanced techniques and equipment from Italy to manufacture urea buttons. Since urea resin cannot be dyed after moulding, colour is introduced already at the raw material stage. Sheets of material are then carefully layered to create natural-looking patterns that capture the rich appearance of horn, nut, and other natural materials. These layered sheets are extruded into long bars, cut into discs, and finally pressed and heat-moulded into high-quality buttons and buckles.

Compared with other button materials, urea offers excellent durability, with superior resistance to weather, impact, chemicals, and heat — making it an outstanding choice for buttons. Its suitability for mass production has also established it as a widely used material across many applications.

Beautiful luster from the southern seas

Celebrated for its shimmering surface and timeless beauty, shell has been used for buttons for thousands of years.

Shells used for button production are mainly sourced from southern seas and islands. Commonly used varieties include pearl oysters, which are often used to produce white or black mother-of-pearl buttons, Trocas shells, and Mexican abalone, almost all of which are imported. As natural materials, their characteristics and quality depend on where they are sourced.

The most widely used is the Trocas shell, which is a material for a wide variety of designs, ranging from thin two- or four-hole styles to shank styles. Unlike relatively flat bivalve shells such as pearl oysters and abalone, Trocas shells have a distinctive conical spiral shape.

Mother-of-pearl is renowned for its brilliant pearly sheen and it is often used on luxury shirts and dresses.

For a long time, shell buttons were handmade, but with the development of processing machinery in the 19th century, mass production became possible. Today, the manufacturing process relies heavily on cutting techniques to shape the surface, which requires specialized techniques.

Natural elegance from vegetable ivory

Buttons made from Corozo, the seeds of the Tagua palm tree native to Ecuador, bring a touch of natural warmth and sophistication. When the outer layer of the seed is removed, the ivory-colored surface beneath is revealed — earning it the names “ivory nut” or “vegetable ivory.” Its beautiful grain and natural sheen are distinctive features.

The production process is meticulous: the seed is sliced to the desired thickness, blanks are cut to size, each piece is shaped, and the surface is polished to highlight its natural luster. This method was first developed by Germans and later mechanized, before spreading further to northern Italy and beyond.

Corozo buttons are often used in menswear.

Buttons with a historic touch

Horn, along with bone and hoof, is one of the oldest materials used for buttons, following nuts and shells in antiquity. In ancient Greece, horn buttons were considered precious accessories, alongside gold and silver.

Common manufacturing methods include slicing solid horns into discs, cutting them to shape, and finishing the surface; cutting open hollow horns, pressing them into flat sheets, and cutting out blanks for further processing; or using the horn tip directly as a toggle button.

In the 19th century, decorative buffalo horn buttons made with an elaborate technique appeared: the horn was cut into a tablet-like form, and pressure was applied to emboss a relief on the surface. Examples exist of horn buttons bearing the portraits of Josephine and Marie-Louise, the first and second wives of Napoleon.

Natural warmth with timeless appeal

Wooden buttons have been produced from ancient times through to the present day. Traditionally, they were cut or hand-carved from single boards of hardwoods such as boxwood, magnolia, cherry, birch, ebony, or olive. Today, however, plywood buttons are the mainstream.

For plywood buttons, thin sheets about 1 mm thick of birch, beech, or lauan wood are impregnated with phenolic resin. They are first dried in the sun for half a day, then heat-dried for about three hours at 60-70°C before being formed to the required thickness. The finishing process is similar to that used for resin buttons, relying on surface shaving machines.

Some designs highlight the wood’s natural grain with burn effects for contrast, and others combine wood with different materials. The natural brown tones of wood vary widely, carrying the unique allure of a natural material.

Buttons with a touch of nature

Leather buttons are made from the hides of cattle, horses, and goats. Most of the raw hides are imported from the Americas and Australia. Leather can be broadly divided into two types: chrome-tanned and vegetable-tanned. For button production, vegetable-tanned leather is primarily used.

The leather is cut to size, shaved to the proper thickness, and then processed in different ways. In one method, strips of leather are carefully braided and then pressed into shape by skilled artisans. In another, thick single sheets are stamped into form. Animal-skin textures can also be imitated by embossing plain sheets of leather. Many designs make use of the leather’s natural qualities — for example, by highlighting the difference in texture between the front and back, or by shaving the surface of dyed leather to create tonal variations, sometimes combined with finishing techniques that give a distressed look.

In the 19th century, a wide variety of leather buttons were produced using many of these techniques. Even today, leather buttons continue to be appreciated for their distinctive look and are commonly used for coats, with production continuing around the world.

Milky elegance

Casein is a dairy product: it is made from rennet casein derived from milk.

In the late 1920s, advances in automated casein production in Germany enabled the material to be manufactured on an industrial scale, and casein buttons soon spread worldwide. In Japan, they were marketed under brand names such as “Lact”, with domestic manufacturing beginning around 1930.

To give casein buttons their luster, color, or patterns, ingredients such as white pigments, pearlescent powder, and water are mixed into the casein and left to cure. The mixture is kneaded under heat and pressure, formed into rods or sheets, and dried for an extended period before surface finishing. Because the process involves careful curing and long drying times, producing casein buttons requires time, care, and the dedication of skilled artisans.

Casein is valued for its warm, natural hand-feel, rich color expression, and the depth and translucency that cannot be achieved with ordinary plastics. Dense yet smooth to the touch, it brings a refined, premium look to garments — such as tailored items, knitwear, or heritage-inspired designs. It is also known for its strength, chemical resistance, and excellent dyeability.