Most factory pages tell you they have "advanced equipment" and "strict quality control." That tells a buyer nothing. This page walks through how a cemented shoe is actually built on our lines, including the numbers our operators work to.

We build cemented footwear only. No injection moulding, no vulcanising. Focusing on one construction is why our sampling runs 7-10 working days instead of the usual two to four weeks, and it is why the process below is standardised rather than improvised.

Why Construction Method Decides Everything Else

Before the first piece of material is cut, the construction method has already determined your tooling cost, your minimum order quantity, your lead time and the material choices available to you.

Cemented construction bonds the outsole to the lasted upper with adhesive under heat and pressure. It sounds simple. The difficulty is that adhesive bonding is unforgiving of process drift. Five degrees too cool in the oven, four seconds too short under the press, and the bond will pass inspection on the day and fail in the field six months later.

That is the reason this page is full of numbers. In cemented footwear, the numbers are the quality.

Stage One: Cutting

Every pair begins as flat material and a set of steel dies.

Die cutting method Four-ply cutting, two face-up and two face-down Dies per component 12 (one for each size in the run) Size range on this run US 5 through US 11

Cutting four plies at once, half of them reversed, is not a shortcut. It is how you guarantee that left and right components come out as true mirror images. Cut them all facing the same direction and you introduce a small asymmetry that nobody notices until the shoe is on a foot.

Two rules govern the cutting room:

Directional materials must be laid out following the approved sample. Materials with a nap, a grain or a woven direction stretch differently along and across the roll. Ignore the arrow on the pattern and the same component behaves differently on the last.

No nicked corners. A component with a chipped edge is scrap, not a repair. The stitcher can hide a lot but not a short edge.

For components that will later be punched or stitched, we pad the die at those positions with EVA. Without the padding the die deforms slightly at the perforation points and the cut walks out of position over a production run.

Stage Two: Stitching

The upper is assembled from ten or more separate components. On a typical lifestyle upper the parts list runs: toe cap, quarter, heel counter, eyestay, front vamp, collar, tongue upper, tongue lower, tongue label, and lower quarter panels for both sides.

Main seams 8-9 stitches per inch Folded and turned edges 10-11 stitches per inch Standard margin 1.5 mm Heel counter margin 1.8 mm Folded edge width 4 mm

Stitch density is one of the fastest ways to read a factory. Too few stitches per inch and the seam has too little grip on the material. Too many and the needle perforates the substrate into a tear line. Between 8 and 9 per inch is where most upper materials sit. We tighten to 10-11 only where an edge has been folded back on itself, because the doubled material can take it and the tighter pitch keeps the fold flat.

One step in this stage is worth calling out, because most factories do not do it:

Every reel of thread is soaked in water repellent for a full 24 hours, then dried completely before it goes near a machine.

Untreated thread wicks. The seam looks fine, the upper material may be treated and hydrophobic, and water still travels along the thread into the shoe. Twenty-four hours of soak time and a full dry cycle costs a day of scheduling and eliminates the problem. On our waterproof programmes this step is not optional.

The rest of the stitching standards read like a list of small disciplines: consistent margins, balanced upper and lower thread tension, no skipped stitches, no floating thread, no bunching, all thread ends trimmed. None of it is glamorous. All of it shows up in a pull test.

Bonded reinforcements — heel backers, eyelet patches, label underlays — are applied with water-based adhesive, sprayed evenly and pressed flat. Water-based rather than solvent-based is a deliberate choice and one that matters for buyers shipping into the EU and North America.

Stage Three: Lasting and Assembly

This is where a flat upper becomes a shoe, and where cemented construction earns or loses its reputation.

Step Setting

Heel counter setting Hot mould 130°C for 35 seconds Cold mould 18 seconds, chilled to a visible frost line Clamp draw 12-15 mm

Midsole and upper drying 70°C ± 5°C actual temperature 3-4 minutes

Toe lasting 25-30 kg pressure 6-8 seconds Wiper temperature 40°C

Heel lasting 35-40 kg pressure 4 seconds Wiper temperature 40°C ± 5°C

Marking 2.5-3 kg pressure

Primer drying 70°C ± 5°C at the upper 2-3 minutes

Read the heel counter line again. Hot at 130 degrees for 35 seconds, then cold for 18 seconds until frost forms on the mould. The frost is the operator's visual confirmation that the counter has dropped below its setting temperature and locked its shape.

Cut the chill cycle short and the counter comes off the machine looking correct. It will relax over the following days. By the time the shoe reaches a customer the heel has lost its structure, and nothing in a standard pre-shipment inspection will catch it, because on inspection day the shoe still looks right.

After setting, uppers are stacked flat and bagged five pairs to a bag. Left loose in a bin, a freshly set counter deforms under the weight of the pile.

The assembly sequence itself runs roughly like this: last and midsole matched to the upper by size, heel counter set, white latex brushed at the heel, upper pulled onto the last with toe and heel centre points aligned, laces tied and a spacer board inserted, adhesive applied to midsole and sock lining at a 15 mm band, oven, midsole attached, toe lasted, waist pulled by hand with pincers, heel wiped, marking, roughing, primer, oven, cement, press, chill, de-last, clean, inspect, pack.

Twenty-six operations from last to carton on this particular programme.

Some of those steps look trivial written down. Pulling the waist by hand is one of them. It is done with a pincer and an eye, inner waist first and then outer, and it is the step that decides whether the finished shoe sits straight or leans. No machine does it as well on a soft upper.

The Two Steps Buyers Never Ask About

Two operations in the list above decide more about long-term durability than anything else, and in fifteen years of quoting we have almost never been asked about either.

The first is roughing and priming. Before the outsole goes on, the lasting margin of the upper is marked with a line, roughed to break the surface, and coated with primer. The primer is then oven dried at 70°C ± 5°C for two to three minutes.

Three things can go wrong here and all three are invisible on the finished shoe. Primer applied past the marked line shows as a shadow above the sole edge. Primer applied too thickly pools and never fully cures underneath. Primer that goes into the press before it is dry traps solvent at the bond line.

That last one is the dangerous failure. The shoe passes every inspection. Six to twelve months later, in a warm climate, the bond gives way at the toe. By then the container has been sold through and the brand is handling returns.

The second is the marking operation itself, run at 2.5 to 3 kg of press pressure with a style-specific marking die. It sounds trivial: draw a line around the bottom edge of the upper. But that line defines where roughing stops and where the sole sits. Draw it 2 mm high on one shoe and 2 mm low on its pair and you have a visible mismatch on the shelf.

Our standard requires the marking height to match left and right, checked against a graded template with one segment per size.

Neither step costs meaningful money. Both require somebody to care on the four hundredth pair of the shift.

How to Read a Factory's Own Documents

If you are evaluating a supplier, ask to see the standard operating procedure for a style they already produce. Not the marketing brochure — the working document the line uses.

Four things are worth looking for.

Does it specify numbers, or adjectives? "Heat until set" is not a process. "130°C for 35 seconds" is.

Does it specify tolerances? A temperature written as 70°C ± 5°C tells you somebody has thought about the acceptable window. A bare "70°C" usually means the number was copied from somewhere.

Does it name the quality risk at each step? Our documents carry a quality note per operation — what goes wrong here, and what it looks like. That section is written by people who have seen the defect.

Is it style-specific or generic? A generic SOP that applies to every shoe in the factory is a filing exercise. A document tied to a specific last, outsole and material set is a working tool.

A supplier who cannot produce this document for an existing style is telling you something useful about how the next one will be made.

What the Numbers Are For

A buyer reading a specification sheet cannot verify most of what a factory claims. Here is what these particular numbers let you check.

Ask any supplier for their heel setting temperature and dwell time. A factory running a standardised process will answer immediately. A factory that subcontracts or improvises will give you a range, or ask to get back to you.

Ask what stitch density they run and why. "8-9 SPI on main seams, tighter on folded edges" is an answer from someone who has thought about it.

Ask whether their thread is treated. Most will not know what you mean.

None of this requires you to be a technical expert. It requires the supplier to be one.

Every Style Gets This Document

The temperatures, pressures and stitch densities above are not generic industry defaults. They are the settings we established for one specific style during full size-run trial production, and they are recorded in a three-part standard operating procedure covering cutting, stitching and assembly.

We produce that document for every style we make. Not only for the large programmes — for a 300 pair order as much as a 30,000 pair one.

There is a practical reason. A style that has been through full size-run trials and has its parameters written down can be reproduced twelve months later by a different team on a different line and come out the same. A style that lives in the head of one technician cannot.

For a brand, that is the difference between a repeat order that matches the original and a repeat order that needs a whole new approval round.

Where Cemented Construction Fits

Cemented construction suits most athletic and casual footwear. It gives wide latitude in upper materials, allows complex outsole geometry, and keeps tooling investment low enough that a 300 pair colourway is commercially sensible.

It is not the right answer for everything. If you need a fully sealed injection-moulded unit, we will tell you so rather than take the order.

What we will not do is quote you a construction we are not set up to run properly.

Specifications Summary

Construction Cemented (cold cement) Size range EU 36-44 adult, EU 30-40 kids MOQ 300 pairs per colour Sampling 7-10 working days on existing lasts Bulk lead time 30-45 days casual and sports 45-60 days boots Production bases China (Jinjiang) and Cambodia Documentation Full three-part SOP per style

Talk to Us About Your Programme

Send us your tech pack, or a reference photo and a target price. We will tell you what construction fits, what it will cost, and how long it will take.

Email duoduo@meike.cn WhatsApp +86 131 1086 5703

Related reading: MOQ, Lead Time and Sampling → /sourcing-info Inside Our Factories → /factory-profile Certifications → /certifications