Inventors come up with ideas at the strangest moments. For example, an inventor in 1937 wrote down concepts for what is considered one of the first modern computers on the back of a cocktail napkin. After a bourbon, he came up with an electronically operated machine that used binary numbers, condensers for memory, a regenerative process to prevent memory loss, and direct logical action for computation. Hard to believe the fundamentals of the device used to type up this blog post (not to mention countless greentech inventions) were originally scribbled on a little paper square.

Provisional patent applications can help an inventor with only a proverbial bar napkin describing his or her invention. It serves as a way to establish an early filing date, mark your product as patent pending, and give the inventor twelve months to test feasibility or gauge interest. The provisional patent application needs to comply with U.S. Patent and Trademark Office requirements for providing a written description of the invention. However, a particular format is not required and no formal patent claim is needed.

Can your (proverbial or actual) bar napkin be filed as a provisional patent application? Yes. I’ve seen provisional patent applications that consisted of a single annotated drawing, a slide deck without any additional explanation of the abbreviated bullet points, or an email. But should such a short document (i.e., a bar napkin) be filed as a provisional patent application? Maybe not. Here’s why.

1. Fewer pages in a provisional patent application can mean fewer details. A provisional patent application only provides a priority date for what it teaches or discloses. If it only has a bar napkin’s worth of scribbles, then details potentially won’t be there when needed in the future. There may be no easy way to later claim additional features under the earlier filing date. And, chances are, very little thought has been given to competing or existing technology. Without careful consideration of how the invention is differentiated, an inventor loses the chance to start crafting claims to avoid competing or existing technology.
2. Speed can be your greatest ally when filing patent applications because you can potentially beat a competitor. However, like doing shots too quickly, it also can be your worst enemy. A hastily-prepared provisional patent application may contain language that negatively impacts an inventor’s ability to make clarifying amendments during prosecution. For example, if your provisional patent application says things like “never,” “always,” “required,” or “necessary,” those statements may be difficult to change later without losing the earlier filing date.
3. Fuzzy language, important features that lack much explanation, or unknown variables in a formula can cause giant, hangover-like headaches later. A short provisional patent application may not be “enabling” or described in enough detail that someone skilled in the art can practice the invention. So the provisional patent application may not provide an early filing date for anything.
4. A bar napkin might only be used for a single drink. Likewise, a short provisional patent application may only cover a single design. An inventor may not be able to later draft claims covering the improved design while keeping the earlier filing date if that design changes. The inventor will be stuck with what’s in the provisional patent application.
5. Like the effect of imbibing too much “liquid confidence,” short provisional patent applications can provide a false sense of security. A quickly prepared provisional application may not cover details related to recent developments or key features. An inventor may falsely assume that it’s safe to freely share details about the invention without a non-disclosure or confidentiality agreement, but is actually risking a public disclosure that will impede the inventor’s ability to obtain future patent rights.

Certainly, a full, formal (and, consequently, more expensive) provisional patent application is not merited in every case. Some technologies may be straightforward enough that a single diagram and a short explanation may be sufficient to lock in an early filing date and fully describe the idea. And an inventor who has experience with patent applications may be able to handle some of the drafting, which can save on patent attorney costs. However, the dangers of filing a proverbial (or literal) bar napkin as a provisional patent application are real. Potential licensees, investors, or partners may be vastly underwhelmed by the inventor’s intellectual property if they discover it only consists of a page or two of jumbled notes. An inventor may find that there isn’t enough detail to get around an examiner’s rejections under the earlier filing date. And, even worse, an examiner may not even give credit to the earlier filing date when claims are examined. So while the groundbreaking invention scribbled on a bar napkin story is a popular example of the American dream, consider using something with more structure and detail when filing a provisional patent application. Use the bar napkin to collect condensation or phone numbers instead.