Most inventors who reach the Enhance Innovations office in Champlin, Minnesota have already shown their invention to someone they should not have. A neighbor who used to work in plastics. A cousin who runs a small ecommerce store. A person at a trade show who said they could "introduce them to a buyer." None of those conversations were under an NDA. Some of them were posted to Instagram. A few went out as CAD files attached to an email.
A prototype here means the thing you show people: renderings, a CAD model, an animation, sometimes a physical model. You can recover from most disclosure mistakes. Some of them, you cannot. The difference is what you did before the disclosure happened, and how fast you act after.
Here is how to protect an invention before it goes in front of anyone. Across 16 years of work with inventors who have made every disclosure mistake there is, the pattern is consistent.
The two clocks running on every disclosure
Two legal clocks start ticking the moment you show your invention outside your own four walls.
The US grace period clock. Under 35 USC 102(b), an inventor in the United States has 12 months from a public disclosure to file at least a provisional patent application. If you blow past 12 months, you can never patent that invention in the US. Public disclosure includes a public sale, a printed publication, a public use, or any other availability to the public.
The international prior-art clock. Most countries outside the US do not have a grace period. The day you make a public disclosure, you have lost foreign patent rights. Europe, China, Japan, Korea, India, almost every market that matters, gone the moment you posted the picture or pitched the buyer without an NDA in place.
If you want US-only protection, the 12-month US clock gives you a runway. If you want any chance at international protection, file before you disclose. There is no second chance and no grace period to lean on.
What counts as a public disclosure
Inventors get this wrong all the time. They assume "public disclosure" means a press release. It does not.
The Instagram post is the one that catches most inventors. They post a "sneak peek" of the prototype. They get fifty likes. They have just lost most of their international patent rights and started the 12-month US clock.
Patent search first, provisional second, conversation third
Before you talk to manufacturers, licensees, retail buyers, or anyone outside your team, two things should happen in order: a prior-art search, then a provisional patent application.
The search comes first because it answers a question you want answered before you spend money on filing or on a pitch. Has someone already disclosed your idea? A real prior-art search reads patents, published applications, and product literature for anything that would block your claims, working against the same record indexed in the USPTO patent search. Doing this well takes search-classification knowledge and access to the right databases. Enhance Innovations runs a professional patent search as a $399 entry step, which is the cheapest way to find out whether the path ahead is open before you commit anything else.
A provisional is the next step. It is not a patent. It is a placeholder that sets your priority date. The USPTO files it without examining it, and you have 12 months from the provisional filing to file the full non-provisional utility patent application.
A provisional written without care is worse than no provisional at all. The priority date you get is only as good as what you disclosed in the provisional. If you describe a hand tool with a single mechanism and 12 months later you file a non-provisional with three additional mechanisms you "thought of later," those new mechanisms do not get the original priority date. They get the date you added them. The provisional has to describe everything you might want to claim, with enough drawings and detail that a person skilled in the art could build the invention.
That detail is where the renderings and CAD from a virtual prototype earn their place, which is one more reason how to make an invention prototype starts with virtual deliverables. A provisional supported by clear drawings of every embodiment is far harder to outflank later than one supported by a rough sketch. Enhance files a provisional patent application for $1,499, drawing on the design work already in hand, so the filing reflects what the invention actually is rather than a thin description written in a hurry.
NDAs: mutual vs one-way, and when each makes sense
An NDA (non-disclosure agreement) is a contract. It binds the recipient not to disclose the information you share. It does not stop them from independently developing something similar. It does not give you a patent. It does not file itself with any government agency.
A one-way NDA protects you. The other party agrees not to disclose your information. You make no commitment about theirs. Use this when you are pitching the manufacturer, the buyer, the licensee. You are the one with the secret.
A mutual NDA protects both sides. Each party agrees not to disclose the other's confidential information. Use this when both sides will share sensitive info, for example a JDA (joint development agreement) where the manufacturer is also disclosing their proprietary processes.
Most early-stage inventors only need a one-way. A simple, three-page, well-written one-way NDA is plenty. Watch for these clauses.
Definition of confidential information. Should include the prototype, drawings, CAD files, business plans, and verbal disclosures during meetings.
Term. How long the recipient has to keep the information confidential. Three to five years is standard for products. Anything under two years is too short for hardware.
Permitted disclosures. The recipient can in most cases disclose to their employees and contractors who need to know, as long as those people are bound by matching confidentiality.
Return or destruction. Recipient agrees to return or destroy your materials at the end of the engagement.
No license granted. The NDA does not give the recipient any rights to your invention. They cannot use it. They cannot make it. They cannot sell it.
Jurisdiction. Where disputes get litigated. As an inventor in Minnesota, you want Minnesota or federal court in Minnesota. Avoid signing NDAs governed by foreign jurisdictions where enforcement is impossible in practice.
If a manufacturer or licensee refuses to sign an NDA, that is a signal. Some big retailers and some public companies have policies against signing NDAs from outside inventors because they get hundreds of submissions and cannot risk being accused of stealing every idea they ever pass on. In those cases, file your provisional first, then submit through their formal innovation portal under their terms. Do not pretend you are protected just because you sent the email.
Witness logs and dated records
Even with a provisional on file, keep a dated record of your invention's development. This is not a strict requirement since the US went to first-inventor-to-file in 2013, but it still matters for proving prior conception in interference disputes and derivation proceedings.
What to keep.
A bound notebook (numbered pages, ink, dated entries). Old-school but accepted in court.
Or a digital research journal with timestamps that cannot be edited after the fact (some patent attorneys recommend platforms that hash entries to a blockchain or use signed timestamps).
Photos with EXIF metadata intact. Shoot prototypes on a phone, do not edit, do not strip metadata.
CAD file version history. Use a system that timestamps revisions and is not editable after save.
Email correspondence about the invention. Even emails to yourself. Each email is timestamped by your email provider.
Witness signatures. When you reach a meaningful development milestone, have someone outside your immediate household witness the prototype, sign and date the notebook entry. The witness should be someone who can later testify they saw the prototype on that date. Not your spouse. A neighbor with no financial interest works.
This level of paper trail seldom matters for solo inventors with simple inventions. It matters more if you are working with co-inventors, contractors, or employees, where ownership and contribution can become disputed.
Sending files and prototypes without leaks
Most of what an inventor shows a manufacturer or licensee today is digital: renderings, a CAD model, an animation. A physical model travels later, and only when a specific party needs to handle one. Both carry their own leak risks.
Digital files. CAD files and renderings are the most sensitive things you will send, because a CAD file is a manufacturing-ready description of the invention, the same files that drive prototype iterations. Send them only to recipients under a signed NDA. Use a shared link that expires and can be revoked rather than a raw email attachment, so access ends when the engagement does. Keep a record of who received which files and when.
Photo and file metadata. When you photograph a model or export a file, the file can carry EXIF or document metadata that includes GPS coordinates, your name, and software details. If you post a photo with location data intact, you have published your home address. Strip metadata before posting or sending (Mac Preview can do this under Tools > Show Inspector > Remove location info, or use a tool like ExifTool).
Physical models, when one ships. If a manufacturer or buyer does need a physical model, often one of the three types of invention prototypes, treat the shipment like a controlled disclosure. Mark cross-border packaging "Sample. No commercial value." for customs. Put a unique serial number on every unit that goes out and track who holds which one. Require return or written destruction at the end of the engagement. Use a courier that requires a signature, not a left-at-door service. For international shipments, a freight forwarder familiar with prototype shipments handles the heavier paperwork.
What to scrub from a sell sheet before sending
A sell sheet is a one-page or two-page document used to pitch licensees or retail buyers. It should sell the product and reveal as little as possible about how it is built.
Include. Product name, problem solved, who buys it, retail price band, photo or render of the exterior, key features, the inventor's contact info, and a clear statement that the IP is patent-pending.
Exclude. Internal mechanisms, exploded views, materials specs, supplier names, manufacturing partner identities, BOM cost, your home address, your phone number's area code if you are concerned about location revealing, and any reference to ongoing patent claims that are still being drafted.
Mark every page "Confidential. Distributed under NDA only." and only send to recipients who have signed your NDA.
A sell sheet is not the right place to disclose your patent strategy or to share the provisional application text. Save those for later in the conversation, with a more specific NDA in place if needed. The same caution applies once a unit is in the field for prototype testing with outside reviewers.
Common mistakes we see in Champlin
Across 16 years of working with inventors, the same handful of mistakes show up every month.
The "I just want their feedback" disclosure. An inventor shows the prototype to three "industry experts" without an NDA because they want feedback. Each of those people is now free in law to do whatever they want with the idea. Some will. Most will not, but you have given up the protection.
The provisional that does not cover what you ended up building. The inventor wrote the provisional on idea v1, then iterated to idea v3. The new mechanism is not in the provisional. When they file the non-provisional, the new mechanism gets a later priority date and may be unpatentable if anyone disclosed something similar in the meantime.
The Kickstarter launch before filing. The inventor launches a Kickstarter campaign with full marketing assets and the campaign is live for two days before they realize they should have filed first. They have started both clocks. International rights are gone in most cases. US clock is now ticking down 12 months.
The trade show booth without booth NDAs. Inventor demos at a trade show. Anyone walking by can take photos. Walking-by photographers are not bound by anything. International rights gone.
The "trusted manufacturer" verbal NDA. Inventor sends CAD files to a Chinese manufacturer based on a verbal "we keep things confidential." Six months later, knockoffs appear on Alibaba. There is no contract to enforce, no jurisdiction that helps, no recovery. The risk is worth weighing before moving from a working prototype to manufacturing.
Each of these is preventable. The fix is the same in every case. File first. Disclose under signed NDA only. Keep records.
What we do for inventors at Enhance Innovations
We are not patent attorneys and we do not file patents. We work with patent attorneys and we structure the engineering and prototyping and disclosure process so the inventor's IP is protected throughout development. That means signed NDAs before the first phone call. CAD files held under our standard confidentiality. Prototypes serialized and tracked. Manufacturers introduced under tri-party NDAs. Sell sheets reviewed for what to leave in and what to leave out.
If you have already disclosed without protection, talk to a patent attorney before you make the next move. Sometimes the situation is recoverable. Sometimes it is not. The next decision is the one that matters.
FAQ
Do I need a provisional before I talk to a manufacturer under NDA?
Not as a hard rule. An NDA gives you contractual protection. A provisional gives you a priority date. If the manufacturer is reputable and the NDA is solid, you can show the prototype before filing. Most inventors prefer to file the provisional first because it costs $1,500-$3,500 through a patent attorney and removes any worry about the manufacturer breaking the NDA.
How long does a provisional patent last?
Twelve months from the filing date. You must file a non-provisional within those 12 months or you lose the priority date. The provisional itself is never examined and never becomes a patent.
Can I file a provisional myself to save money?
In strict legal terms, yes. The USPTO accepts provisionals from non-attorneys. Most provisionals filed without an attorney are written too narrow to support the eventual non-provisional claims. The $1,500-$3,500 you pay an attorney for a well-drafted provisional is in most cases worth more than the priority date you would lose with a self-filed one.
Is a poor man's patent (mailing yourself an envelope) real?
No. The poor man's patent has never been a recognized legal doctrine. Mailing yourself a sealed envelope does nothing of legal value. The US went to first-inventor-to-file in 2013, which finished off whatever weak claim the practice ever had.
What if I already posted my prototype on social media?
Talk to a patent attorney now. In the US, you have 12 months from the post to file a provisional or you lose US patent rights too. International patent rights are gone in most cases. Some jurisdictions have a six-month grace period for inventor-originated disclosures, but most do not.
Can the manufacturer steal my idea even with an NDA?
An NDA gives you a legal cause of action if they breach it. Whether you can enforce it in practice depends on their jurisdiction, their assets, and your appetite for litigation. NDAs deter casual theft. They do not stop a determined bad actor in a jurisdiction with weak IP enforcement. Pair NDAs with patent filings and pick manufacturers with traceable business histories.