Understanding the different shoe manufacturing methods is crucial for making informed decisions when outsourcing your shoe production and to devise a shoe quality control plan. Each shoe manufacturing method has its own unique advantages and disadvantages. Here, we explore five of the most used techniques in factory.
Cemented Shoe Construction
Cemented construction is a popular method for producing casual and fashion shoes. This technique involves attaching the shoe’s upper to the outsole using adhesive. It is cost-effective and simple, making it ideal for mass production as it requires fewer skilled artisans. During the final inspection, it is essential to check the strength of the attachment. Ensure that the adhesive is applied correctly—neither too much, which can affect the shoe’s appearance, nor too little, which can compromise the bonding strength.
Goodyear Welted Shoe Construction
The Goodyear Welt method is renowned for producing high-quality and highly durable shoes and boots. This technique involves stitching a leather strip, known as the “welt,” around the upper and the insole, which is then attached to the outsole. You can easily identify Goodyear welted shoes by the two rows of stitching: one on the inside where the upper edges meet, and another around the outer sole.
Producing Goodyear welted shoes requires skilled artisans due to the complexity of the process, making these shoes more expensive than others. During quality inspections, it is crucial to check that the stitching is even and the bonds are strong. Inspectors also ensure the symmetry and alignment of the shoe’s form, maintaining the high standards expected of this construction method.
Blake Shoe Construction
Blake construction is commonly used for formal shoes. Similar to the Goodyear method, it involves stitching the upper, insole, and outsole together. However, unlike Goodyear construction, Blake shoes do not have a welt; instead, the outsole is directly attached to the insole. This method is typically handcrafted by experienced artisans, making it more expensive to produce.
During quality control inspections, the focus is on ensuring the consistency of the stitching and the proper alignment of the shoe’s parts. Inspectors also check the shoe’s structural integrity and aesthetic appeal to maintain high standards.
Direct Injection Shoe (DIP) Construction
Direct Injection Shoe (DIP) construction is often used for work boots and outdoor shoes due to its durability and support. In this process, the footwear upper, midsole, and outsole are molded together using a machine that injects materials at high pressure into the shoe’s mold. This method creates a seamless shoe with no stitched parts, providing high production efficiency and consistent quality once the molding process is properly set up. Typically, this method is used in larger factories that have the necessary machinery and skilled workers. Quality control for direct injection shoes begins at the initial stage, ensuring that the sample produced by the mold is correct and approved. The molding process must be set up precisely and correctly to maintain high standards.
Vulcanized Shoe Construction
Vulcanized shoe construction is commonly used for sneakers and canvas shoes. In this method, the shoe’s rubber outsole is attached to the upper using heat and pressure. Vulcanization is cost-effective and offers a fast turnaround time, making it a popular choice for many brands. During the quality control process, it is crucial to identify any defects caused by the heat and pressure during the attachment and vulcanization processes. Ensuring the materials are not adversely affected by these processes is key to maintaining the shoe’s quality.
We help buyers to deploy footwear technicians to implement a comprehensive quality assurance program that covers every stage of production. The quality assurance program includes incoming materials QC, where we inspect and verify the quality of all incoming materials to ensure they meet required standards before entering the production process.
During production, we conduct pre-production meetings with artisans and factory staff to align on production standards and expectations, including a pre-production meeting to discuss the production plan, quality standards, and potential issues, and an artisan meeting to ensure skilled workers understand the quality requirements and production techniques.
We perform a detailed inspection of the first batches produced to ensure they meet quality standards before continuing with full-scale production. In-process QA involves monitoring each step of the production process, from cutting and stitching to lasting, to ensure consistent quality and address any issues immediately.
Finally, pre-shipment QC includes conducting a final inspection of the finished products before they are shipped to ensure they meet all quality standards.
We provide learning classes for factory QC staff and supervisors to promote a culture of quality and continuous improvement, including face-to-face facilitator learning sessions where facilitators provided in-depth training on quality standards and inspection techniques, and 1:1 coaching on the shop floor to address specific issues and reinforce best practices.
Additionally, we help to improve and refine processes across all departments to eliminate waste and inaccuracies that lead to reworks or rejects, focusing on precise cutting to avoid waste and ensure consistency, improving stitching techniques to enhance durability and appearance, and refining the lasting process to ensure the final shape and fit of the footwear are consistent and meet quality standards.
In the pre-shipment inspection of footwear, we follow a AQL chart for the product sampling. Our inspection procedures include a thorough examination of the final workmanship. We perform various tests, including fit tests and size measurements, to confirm that the shoes or boots fit correctly and comfortably. The strength of bonding between the upper and the outsole is checked to ensure durability, and we verify the alignment of the shoes to maintain aesthetic and structural integrity. Our inspection process also involves a detailed review of the stitching to ensure it is even and secure, and we check that all materials are correctly inserted according to the design specifications.
KOL Quality can assist with quality checks for your footwear products on demand. Our inspectors, who have a background in footwear technology, are adept at ensuring the quality of your shoes. We provide shoe quality control service in the major shoe manufacturing cities in China, India, Malaysia, and Vietnam. Based on the type of your shoes and their manufacturing method, KOL Quality can help devise the most suitable quality control plan for your shoe manufacturing needs. We inspect your items and confirm they meet the required standards before they reach your storage. This is particularly beneficial for online sellers, brands, and stores who strive for good review products but cannot visit the factories themselves. With KOL Quality, you receive expert inspections to ensure your product quality remains impeccable.
Pre-shipment inspection is the best practice to manage the quality of production if you are buying a significant quantity of products. Normally buyers spend 3-5% of cost of product in pre-shipment inspection. The benefits of pre-shipment inspection include but not limited to the following:
There are several parties can help to perform pre-shipment inspection and the pros and cons are illustrated as below:
| Pros | Cons | Best Practice |
Third party inspection company | – Impartial – Only represent you – Resourceful – Professional – Good after sales service – Systematic – Clear whistle blower channel | – Not worth for low shipment value
| If your shipment is worth more than USD 4,000 or if you have faced quality problem before, it is worth to buy inspection service from third party inspection company |
Sourcing/Trading Company | – Can be focus – Resourceful – Good after sales service
| – Usually they represent both buyer and factory – Not professional in quality control | If your shipment value is lesser than USD 4,000, you may delegate the inspection job to sourcing/trading company by setting up a good resolution contract |
Individual/Freelancers | – Lesser cost – Can be professional – Can be flexible | – Lack of systematic approach – Vary service quality depends on the individual’s ability – Risk of no after sales service | If you have been introduced to a trustable individual/freelancer and you have done the due diligence. |
Factory self-inspection | – Save cost – Professional in product making | – Potential of negligence as no other perspective to check the quality – Conflict of Interest | If this is a continuous lot of production, there is no significant changes of production and no quality issues in first shipment. Occasional inspection by third party is advice. |
Firstly you will be contacted by a quality facilitator to discuss your product and the quality checking criteria. Once you place order to the supplier, you are encouraged to share the contact of supplier with the quality facilitator as he/she will help you to follow up on the production schedule and arrange for the inspection once the product is ready for pre-shipment inspection. A pre-shipment inspection shall be conducted when 100% product is finished produced and 80% is packaged.
A pre-shipment inspection shall be conducted when 100% product is finished produced and 80% is packaged. For first inspection, you are advised to contact us 5 working days in advanced as our quality facilitator will tailor made a best plan for you.
KOL Quality has built a library of checking criteria for a broad range of products. Having said that, we believe all products are unique to the brands and our quality facilitator love to discuss the checking criteria together with you.
You will normally get the pre-shipment inspection report within 24 hours in working days (Monday to Friday).
We will inform you the result on the same day of inspection if the result is failed and we advise you to discuss with suppliers for a resolution or rework plan. Quality facilitator from KOL Quality is always aside if you need help in the communication.
