The footwear materials you select for your shoe design are what make your shoemaking ideas come to life! You will find the shoe pattern is not the critical or special feature, the footwear materials are! Learning how to specify footwear materials is critical when you are learning how to make shoes! If you want to learn how to become a shoe designer, you must know how to spec footwear materials. You have an infinite menu of material choices and colors to create your footwear masterpiece. Rich leathers, silky mesh, or high-tech synthetics, take your pick.
The shoe designer must take great care to pick the right materials that can stand up to the demands of shoemaking. The demands for footwear performance and manufacturing must be met. A beautiful material that rips during the lasting operation or fades in sunlight can’t be used! So let’s learn how to select footwear materials.
Factors for Shoe Design Materials:
When you select footwear materials for your projects the shoe design brief should help guide your choices. The design brief defines the type of shoe you are making: a ballet slipper for a dancer or work boots for lumberjacks? What is the best sneaker material? What are the best running shoe materials? Are these going to be inexpensive or premium shoes? With your design brief in hand and some background knowledge, you can select the right materials suitable for your shoe design.
The most common materials for shoes are leathers, textiles, synthetics, rubber, foam, and plastic. Each has its specific uses in footwear. Depending on your design, each material will have a place in your shoe. Material selection is one of the fundamentals of shoe design. Let’s take a quick tour of these common materials.
Leather for Shoes
Cow leather is the most common material used for making shoes. It is durable, flexible, stretchable and is available in many styles, colors, and prices. It is truly a great material, you can make beautiful functional and fashionable shoes.
Real Leather is alive! Not really, but the character of leather changes as it wears. A fine leather shoe breaths and conforms like no other shoe. A handmade leather shoe can be a masterpiece of a shoemakers craft. But, leather does have some drawbacks. It can be heavy, hot, and susceptible to water absorption and damage if not treated. Water-resistant and water-proof treatments add cost. Leather is a relatively expensive material when
compared to fabric or other man-made materials and must be treated with care during shoe manufacturing.
Because leather hides are from individual animals, each is a different size and each will have scars, imperfections, even brands that must be avoided when cutting. This uncut material is called cutting loss. For leather, cutting loss is at best 5% of a hide, for the highest quality shoes, shoe leather cutting loss can be 15%. That’s 15% of the material cost being thrown away.
Textiles for shoes come in a huge variety of colors, weaves, knits, fibers, and denier. Denier is how thread weight is measured. 1 denier = 1 gram per 9000 meters of thread. Typical denier is 110D for very lightweight fabric, 420D and 600D are common in shoe fabrics. Footwear textiles come in many fiber types including cotton, wool, nylon, polyester, polypropylene, rayon, lycra, and many others. Each has its own look and physical properties.
What are athletic shoes made of?
Textiles are a miracle material for shoes! With an infinite variety of weaves, colors, patterns and special features, textiles have a special place in footwear design. You will find textiles inside and out on footwear and even on the bottoms. Man-made polymer fibers such as nylon and polyester are lightweight and durable. Lycra is stretchable and cotton canvas is a must for vulcanized construction and has a look all its own.
Depending on the import rules for your country, textiles are often a higher duty rate. Shoes made with 51% textile surface area are sometimes 20%. A textile shoe costing less than $12.50 USD will be 20% +.90 duty! (depending on the country of origin). However, there is a trick, by molding textile on the sole of the shoe you can avoid the high duty rates! Textiles will be reviewed in-depth in their own article.
Synthetics for shoes
Whatever you call it, synthetic, synthetic leather, PU leather, or just PU, this material is another must-have for modern sports shoes. This class of material offers the shoe designer a huge variety of colors, textures, and features at a wide range of prices. It was once considered to be cheap junk not suitable for high-quality shoes, times have changed! These man-made materials are often a composite made of two layers. A backing layer made of woven or non-woven polyester fibers combined with an external surface by “dry” lamination process or by liquid “wet” processes. Many of the least expensive synthetics have a fibrous woven backing with PVC skin made by a wet process. The surface on these may not be 100% smooth and the shoe will show wrinkles and creases. This material is the cheap stuff found on inexpensive shoes.
High-end leather starts with a water-resistant microfiber PU backing. This backing has a smooth surface, cuts cleanly, and can be dyed to match the surface materials. A microfiber style backing can be ordered in .5 to 2.00mm thicknesses, has some stretch, and can have a water-resistant treatment. On top of this backing, the skin can be applied.
Polyurethane plastic film .2 to .5mm thick is made in a separate operation and the two layers are then rolled together with heat and pressure. PU outer skin is then printed, embossed, scuffed or polished to create one of the millions of surface options. The largest PU maker has hundreds of different embossing patterns that can be applied to hundreds of different surfaces. If you can meet the order volume required, you can pick any color you want! Synthetics will be reviewed in-depth in their own article.
Foam for Shoes
There are many types of foam used to make shoes, here we are going to review the types of foam found in the uppers of shoes. Generally, foam is divided into two types, “Open Cell” and “Closed Cell” foam. Open cell is exactly what it sounds like, the plastic compound that makes up the foam cells is open, air and water are free to enter and exit the foam just like a dishwashing sponge. Closed-cell foam is exactly that, individual cells are closed or sealed not allowing the foams internal gas to escape.
Open-cell foam is generally softer, these foams are made of Polyurethane plastic. This type of foam is commonly known as “KF or KFF” foam. Open-cell foam is available in different densities and in almost any thickness and color. Open-cell foam is used in the tongues and collars of shoes. Thin sheets of PU foam are used to back fabric in most shoes uppers. PU foam allows the stitches to sink in and gives mesh some extra support while reducing wrinkles.
Reticulated foam is the most open style of foam. This type is often used for ventilation features.
Closed-cell foam is generally denser. Midsoles of shoes are all made from closed cell foam. Midsole foam is covered the article Outsole Design. Common Closed cell foams include EVA (ethyl vinyl acetate), PE (Polyethylene), SBR Styrene butadiene rubber), PU (Polyurethane), Latex, and Neoprene are the most common types. Each has its own properties. EVA foam is used for backing mesh materials, 2mm sheet EVA will make the fabric waterproof. Neoprene and SBR are used when elastic properties required. Latex is common for collar linings. PE foam is very light but not so durable so its use is limited.
When working with foam it is important to know what foam is appropriate for the shoe upper and what is appropriate for cushioning the shoe outsole. Learn more here.
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