Possibly the most common type of iPhone cases are the ones made out of hard plastic or also commonly referred to as shell cases. They're the most popular as they tend to be easy to install, in most cases they just snap on and provide the most amount of protection for the least amount of money. For example, while the average hard plastic case costs $3-$5 a similar soft silicone case might cost $8-$10. The spike in price is due to the material these plastic cases are made out of. All hard plastic case with the exception of a few customized styles are made out of Thermoplastic polyurethane or TPU for short. TPU is a type of plastic which is very common is the manufacturing world. It's made out of a hybrid combination of diisocyanates with short-chain diols; this chemical blueprint can be almost indefinitely modified and adjusted depending on the type of plastic result you want whether it be more flexible or slightly rigid. TPU can be found being used in home appliances, computers, cars and many other things but the plastic has found huge success in the smartphone cases industry. This is because TPU is so flexible and can be easily adapted to the fit any type of design you're trying to create be it textured, smooth, painted or clear. It's resilient to scratches or cracking and can be effortlessly cleaned if dirtied. Combine these attributes with the fact that it's largely available making it relatively cheap for manufactures to obtain and you've got the best material for making smartphone cases.

Because TPU is such a flexible material it's quite easy to work with making the manufacturing process of the cases simple and straightforward. After the dimensions of the iPhone case have been taken a mold is created to scale with the desired shape and texture of the case. Raw TPU material is injected into the mold as a liquid and quickly cooled into a solid inside in order for it to take shape. Once the mold is cooled the case is taken out and prepped for painting or printing. Most designer use Spot UV Printing to transfer a design or color onto the case, Spot UV gives a better end result with sharper and brighter colors that won't fade away. The last step is to add a protective coat which can be either shiny or matte depending on what the designer desires.

Aside from the flexibility and low cost of producing a TPU iPhone 5 Case offers, there is also a large array of protective properties and functional usability. For one, these cases are light weight but highly resilient to scratches and scuffing. This is important because that's one of the main reasons you’d want to install cases, to protect against small nicks and dings from reaching your phone’s outer shell. They're easy to clean and particularly resistant to oils making them practically maintenance free. Because they're slightly flexible most of these cases are designed as a snap on style delivering a quick and easy install process. The smooth clean surface is an ideal canvas for designers to print their unique graphics onto them making them truly one of a kind and giving them more appeal rather than having solid color finishes. Lastly, once installed they provide a protective barrier to keep dirt and dust away from your phone to keep it looking good as new.