Skin or vacuum packaging involves a plastic film that is molded over the product to a backing using a vacuum. The item is securely affixed to the backing by the film. Film thickness is easily changed, and no special tooling is required. This type of packaging allows for multiple product types to be packaged simultaneously. Skin packaging works for small- to large-scale production. A strong benefit to this method is that it allows good visibility for consumers in a retail environment. This method is often a bit less expensive than its cousin, blister packaging, but to use one or the other is usually decided based on function rather than cost.