Holsters are commonly used alone for devices that include rubberized padding, and/or are made of plastic and without exposed rigid corners. Heavy duty cases are designed to protect from drops and scratches.
A Standing (or kickstand) case keeps the device standing upright. The claspible kickstand of some horizontal cases holds the device in a more flat or steep angle, depending on whether it is horizontally placed on a surface clockwise or counter-clockwise. The flat angle allows tapping without pushing the device over, while the steep angle is intended for watching.
Skins and design covers can serve for protection and personalization. These are the result of the relatively "naked" designs produced by manufacturers such as Apple, where the metal and glass components of the device are exposed and vulnerable to damage. They are distinct from holsters, in allowing use of the device while in the case, but in many instances include a belt clip or other device giving it the functionality of a holster. They are made of hard plastic, rubber, silicone, leather, or adhesive-backed vinyl pieces. Vinyl material may be calendared or cast, with the latter being more expensive. Calendered vinyl is expected to only be used for short-mid duration (10 years), while cast vinyl is used on a more long-term basis. Calendered vinyl also tends to shrink in the heat and can be shaped into any form (above 80 degrees Celsius), and may fade in direct sunlight.
Customized phone cases use custom printing. Different companies have different methods of printing on cases; some utilize sublimation, others Inkjet-printed skins, others dye-sublimation 3D printing methods.