Contents

Goodyear Welted Construction
The Leather Upper
Shoes Assembly
Finishing the Shoe
Sewing Thread Quality Perimetres
Extension Modulus
Elongation at Break
Elasticity
Inseam welt sewing / Single thread chain-stitch 101
Outseam stitching / Double thread lock-stitch 301
Welted Needles / Awls Recommendations

Goodyear Welted Construction

Goodyear welted construction is the traditional method of attaching sole to upper to achieve a mechanical join. The Goodyear desription takes its name from Charles Goodyear, the man who in 1869 invented a mechanised way of making the join. He therefore replaced the earlier completely hand sewn method. 

The shoe’s unique quality is that the sole can be replaced many times, allowing the wearer to build up the highly desirable “patina” effect achieved through years of wear. This method of construction and the material component quality used results in shoes that can last up to 20 years, or longer, depending on the treatment and condition of the uppers.

Shoe Construction

There are 174 processes and 210 operations that go into making a pair of high quality Goodyear Welted shoes and thread is regarded to be one of the most important components.

The Leather Upper

The shoe uppers are cut from selected calf hides that are much softer than the soles, and then pressed to a uniform thickness. In order to keep leather waste to a minimum, the uppers are carefully cut by a skilled craftsman. First, the tip, vamp, quarter and tongue are cut, then the brogue’s holes are punched into them. The edges of the uppers are shaved in order to prevent a thick layer forming where they overlap or fold. To reinforce the uppers a piece of flannel, called the doubler, is glued to the leather upper from the inside, before the tip is stitched to the vamp. Later, the lining is sewn together and stitched to the quarters, once done the eyelets are applied from the inside. Finally, the vamp and the quarters are stitched together, resulting in the finished upper. 

Shoes Assembly

Assembly starts by pulling the uppers over the last and tacking with nails; a canvas lip band of the sole is attached to the uppers (except for the heel area). The upper leather is tacked to the last and a few temporary tacks are applied to the front, before the upper edges are trimmed. The Goodyear Welt is sewn to the upper leather, through the rib on the sole; a wooden shank is added for strength and stability, and cork filling is put between the inner and outsole, to provide some cushioning for the foot.

Next, the outer sole is cemented to the rest of the shoe under high pressure; the sole is attached by adhesive and then shaped to fit the rest of the shoe. After this the thread is stitched to attach the upper to the sole. This can mean stitching through leather thicknesses of up to 2cms in order to hold the materials firmly together. Mass produced shoes are sewn by machine, but bespoke shoes are usually sewn by hand.

Finishing the Shoe

Hot vibrating irons are used to pound the edge of the sole, to give a hard, rounded, smooth and polished surface; the leather heel is nailed to the sole and the sole receives its final trimming. At this stage, the shoe construction is almost complete, but a number of finishing operations remain. The uppers and the welt are cleaned and polished; the soles are polished with wax and the last is taken out of the shoe. The shoes are then sprayed to give them a uniform shine and lustre, then after a final inspection, the shoes are wrapped, boxed and shipped to the retail shops.

It is essential the threads chosen have the correct technical properties to ensure good stitch-ability, consistent balanced lock and seam durability. Thread with inconsistent friction levels, or excessive extensibility, can lead to poor stitch balance which can cause premature separation of the sole during wear.

Sewing Thread Quality Perimetres

A number of sewing thread tests can be carried out which will give a good indication of the resultant quality of the sewing performance and seams:

• Extension Modulus 
• Elongation at Break
• Elasticity

These are all qualities of particular importance in the area of Goodyear welted stitching but are perhaps not well understood because the terms can be confusing. If ignored, they can lead to costly returns and damaged brand reputation. It is important to understand the difference between these terms. 

Extension Modulus

Extension Modulus is the elongation of a thread under a given load: how much it stretches under 1 kilo load, 2 kilo load etc. Tests are carried out under increasing loads which are then plotted and compared. The importance of this is to control the elongation at low loads which helps to prevent skipped stitching and importantly, for welted shoes, the “tightness” of the seam to prevent shearing and separation. 

Elongation at Break

If a length of thread measuring 100cm can be stretched to break at 110cm, it has 10% elongation. Elongation is simply the extent of stretch expressed as a percentage of the original length at break. 

Elasticity

Elasticity refers to the ability of a thread to stretch and recover to its original length. If a thread is stretched and it fully recovers to its original length, it is said to have 100% elasticity. 

Inseam welt sewing / Single thread chain-stitch 101

This stitch, used for inseam welt, is not open to any damage in wear and cannot be easily seen when the shoe is finished.

It is therefore more suited to the relatively long (8mm) stitches normal for this operation. The thread is passed through a hot wax pot which ‘sets’ its characteristics and seals the awl holes to prevent water ingress. This is a critical seam for Goodyear welted footwear; if not done correctly, with the right thread and seam setting, the whole shoe can be ruined.

Outsole stitching / Double thread lock-stitch 301

On the outsole seam, stitch tensions should be set to achieve the correct lock according to material thicknesses involved. The ideal position is one-third into the sole from the interface of welt and sole; this minimises the risk of any seam failure. 

If the lock is positioned at either the interface of sole and welt or close to the sole groove, premature failure can occur quite quickly during wear.

The bobbin thread is waxed, which helps to create a rigid “holding peg” for the top thread. This prevents the detachment of the sole from the welt, after the bobbin thread is worn away through wear. This also helps to improve the water resistant properties of the shoe.

Welted Needles / Awls Recommendations

The nature of this shoe construction means that Goodyear welted shoes take much longer to manufacture than less expensive alternatives. Factories employ experienced, highly skilled operatives to create dress shoes of comfort and durability. It is not uncommon to find mass produced shoes up to a retail price of £400; while bespoke shoes can cost up to £5,000 per pair.

Work Type	Inseam Welt Stitching	Outsole Needle Size	Outsole Awl Size	Outsole Needle Thread	Outsole Bobbin Thread
Heavy - With Through	64s HS Polyester	45	43	9s Coretex	4M Dual Duty
Medium / Heavy - No Through	64s HS Polyester	47	45	6s Coretex	5M Dual Duty
Light / Womens	64s HS Polyester	50	47	6s Coretex	5M Dual Duty

The Goodyear welted construction is the chosen method for some highly reputable brands in the shoe industry, for whom Coats is the supplier of choice; these include Barker, Churches, Alfred Sargent, Cheaneys, John Lobb, Grenson Ltd, Loake Shoes, R E Trickers, Sanders & Sanders.