Sending your part to a stranger: what really happens to your 3D file when you request a quote

There is one objection that comes up in almost every initial conversation and that almost no one says out loud: to request a quote, you have to show the part.

In machining, this is less of a problem, because there's still a lot of skill involved in getting from a blueprint to a manufactured part. In additive manufacturing, it's different: the file is the part. Whoever has it, can manufacture it. And often, the geometry is precisely what sets a company apart from its competitors—the result of years of testing, or of a development that hasn't yet been published.

So the question is reasonable, and deserves a better answer than "relax, we're serious."

What the law protects and what it doesn't

It is important to separate three things that always get mixed up:

Patent. It protects an invention, not a file, and only if it has been granted and is in force where applicable. Furthermore, it is public: a patent is the exact opposite of a secret.

Trade secrets. In Spain, this is regulated by Law 1/2019. It protects information that is secret, has value because of its secrecy, and for which its owner has taken reasonable measures to maintain secrecy. This last condition is what matters here: if you send the file around without any control or agreement, you are weakening your own protection. Negligence is not only a practical risk; it is an argument against you if a claim needs to be made in the future.

Copyright. It covers the file as a work in some cases, but not the function of the part. For industrial geometry, it is a weak and not very useful protection.

The practical conclusion: what truly protects you on a daily basis is the contract and control over who has the file, not the registry.

{!This section is for informational purposes only, not legal advice, and should be read as such. Samylabs should have its legal counsel review it before publishing, especially the references to Law 1/2019 and the confidentiality periods.!}

What should a useful NDA say?

A two-page confidentiality agreement downloaded from the internet isn't very useful. The points that actually make a difference are:

What constitutes confidential information, explicitly including CAD/STL files and everything derived from them: parameters, toolpaths, reports.
Single purpose: to evaluate and, if applicable, manufacture that part. Nothing more. Without this, "we use it to improve our processes" falls within the scope of the term.
Prohibition of reverse engineering and manufacturing for third parties based on that file.
Subcontractors: if your supplier outsources post-processing or heat treatment, who oversees what? This is almost always overlooked, and it's where information leaks.
Term: confidentiality must outlast the contract. Five years is short for a product part; trade secrets can be agreed upon indefinitely as long as they remain secret.
Certified return or destruction upon completion, with date and proof of delivery.
Applicable law and jurisdiction. An excellent NDA with jurisdiction ten thousand kilometers away is merely decorative. It is one of the practical reasons —beyond the discourse— to look at European suppliers and machines.

The questions that reveal more than the NDA

The contract says what should happen. These questions say what actually happens:

Where is the file stored and for how long? "On our server" and "forever" are two different answers, and both are given.
Who has access within the company? Sales? The entire shop floor? Or only the person preparing that particular build?
Is the quoting system yours or a third party's? Many automated quoting tools in the industry are external platforms: your file ends up in a cloud that isn't your provider's and over which your provider has no control.
Is it deleted when the job is finished? Do you have to request it, or is it done automatically?
Do you manufacture for my competitors? This isn't an aggressive question: it's a risk management question, and an evasive answer is already information.
If you subcontract something, what does the subcontractor see?

What you can find out without sending anything

Much of what you need to decide doesn't require anyone to see your part:

Material volume and final mass.
Dimensions and whether it fits on the build plate.
Build height and number of layers, which determines machine time.
How many units fit per platform.
An order of magnitude of the cost.

All of this stems from geometry, and your own computer can measure geometry. That's why the quote calculator on this website works the way it does: you upload the STL file, the browser reads it, and the calculation happens on your machine. There's no upload, no copying to any server, and nothing you'd ask us to delete, because we've never had any. You can disconnect from the internet as soon as the page loads, and it will continue working; if you want to test it, this is the fastest way.

It's not a marketing gimmick: it's the correct technical response to a legitimate objection. The conversation with us begins when you already know if you're interested.

A reasonable ladder

How would we approach it if the part is sensitive?

Numbers first, no file. Volume, deadline, order of magnitude. If it doesn't add up, you haven't taught anyone anything.
Technical discussion with the part covered. You can talk about materials, tolerances, post-processing, and qualification by describing the part without sending it.
Signed NDA, with the points above.
File, and only then. If possible, a simplified version or a representative part for the first test.
Closure: return or certified destruction, in writing.

Anyone who objects to point 3 is telling you something important before you've even given them anything.

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What else should you ask before sending a part to be manufactured? Find out in twelve questions for an additive manufacturing supplier. How to prepare the file so the quote is realistic? Find out in preparing the file: STL, 3MF and the mesh. And when you want to stop sending files out, check out ALBA 300 and ALBA 500 for in-house manufacturing.