TL;DR
Understand who owns the design under each model, how sampling and cost behave, when a mixed assortment makes sense, and which questions to settle in writing before the first sample.
The difference is who brings the design
Under OEM, the buyer provides the design, the specification and often the artwork, and the factory manufactures to that brief. Under ODM, the factory offers a developed style from its own range, and the buyer selects, adjusts and brands it.
This is a commercial distinction as much as a technical one. OEM work is built around your document; ODM work is built around a style that already exists and can be modified within defined limits.
What changes under each model
OEM gives control over silhouette, materials, trims and packaging, at the cost of more development time and more documentation. ODM moves faster because patterns, grading and construction already exist, but changes are usually limited to fabric, colour, trim, label and packaging rather than a new silhouette.
A practical test is to ask what can change without a new pattern. If the answer covers colour, fabric and branding only, you are working in ODM territory.
Cost and sampling behaviour
OEM sampling usually requires pattern development, a first sample and often a second fit or pre production sample. ODM sampling is quicker because it starts from an existing pattern. In both cases, sample charges are quoted per project and are usually discussed together with the production order rather than as a standalone service.
Ask whether the sample fee is credited against the order and whether tooling, such as a print screen or a custom mould, is charged separately. Written answers here prevent surprises at the purchase order stage.
Exclusivity and design rights
ODM styles can be offered to more than one buyer unless an exclusivity arrangement is agreed. If your assortment depends on a style looking distinct, confirm in writing whether the style is exclusive to you, for which markets and for how long.
For character or licensed designs, rights are a separate matter from OEM or ODM. The buyer normally confirms that it holds the right to use the artwork and provides that confirmation before production begins.
Choosing per style in one assortment
Most assortments benefit from a mix. A core range of ODM styles covers the volume and price points quickly, while one or two OEM styles provide the signature pieces that differentiate the collection. Splitting the range this way keeps development effort where it earns the most.
Shanghai Haitailu Clothing Co., Ltd supports both paths from one production base, and the catalogue at www.festivocostumes.com shows the ODM side of the range by series, with OEM development starting from artwork or a reference garment.
Related on this site: OEM and ODM services · Wholesale costume catalogue · Discuss a development brief