These two terms get used interchangeably, but they describe different things. Understanding the difference helps you ask manufacturers the right questions.
Custom blending: your formula
Custom blending means a manufacturer produces a specific recipe — usually one you supply or develop together. The flavor is unique to your product.
Private label: your brand
Private label means a product is sold under your brand name while being manufactured by someone else. In some programs, the formula comes from the manufacturer; in others, it's the brand's own.
When brands use both
Many successful seasoning brands combine the two: their own recipe, produced by a manufacturing partner, sold under their label. If your flavor is your differentiator, this is often the path.
Questions to ask
Who owns the formula? Is it produced exclusively for you? What does the manufacturer need from you to begin? Get clear answers in writing before you commit.