Back in July of 2016, Apple filed a patent for a paper bag – here in May of 2017, Apple has been granted that patent.
A patent is only granted to innovative and novel devices, techniques, methods, and processes. Because apparel, accessories, and designs are artistic creations, it is not possible to patent them.
You absolutely can get a patent on a bag. There's even an entire classification in the IPC (International Patent Classification) just for backpacks (IPC A45F).
For example, the laws of nature, physical phenomena, and abstract ideas cannot be patented, nor can only an idea or suggestion. Other restrictions include the patenting of inventions exclusively related to nuclear material or atomic energy in an atomic weapon (see MPEP 2104.01).
If you ever transported groceries from the store, or packed a lunch for work or school, chances are you're familiar with Margaret Knight's invention—the flat-bottomed paper bag. This was the most famous of several inventions that Knight patented at the end of the 19th century.
Eventually, a patent for an open-mesh, fabric Tea Leaf Holder was filed in 1901 by Roberta Lawson and Mary McLaren of Milwaukee, Wisconsin. Other designs soon followed. During the 1920s, technological advances in the US-led to the development of machinery that could make and pack gauze bags.
To put it in simple words, a design patent protects the appearance of an innovation or product packaging. Utility patents are more well-known to the public. These types of patents cover an invention's practical or functional elements. As a result, they are frequently focused on tools and methods.
For instance, while a material may conventionally be used as a structural material, its use as a refractory material, or its use as a dielectric material in an electronic device, may be patentable.