If you’re planning to buy the gloss back iPhone 7 or iPhone 7 Plus, you may want to order a case to protect the phone as it can be easily scratched. Apple added a footnote on the iPhone 7’s webpage which states:
The high-gloss finish of the jet black iPhone 7 is achieved through a precision nine-step anodization and polishing process. Its surface is equally as hard as other anodized Apple products; however, its high shine may show fine micro-abrasions with use. If you are concerned about this, we suggest you use one of the many cases available to protect your iPhone.