ETcH vs INPI: which solution to protect your creations?

For decades, the Soleau envelope was the go-to for French inventors and creators. Filed with INPI, it proved the existence of an idea at a given date. But the landscape has changed.

A brief history: from the Soleau envelope to e-Soleau

The Soleau envelope (1910-2020)

A simple device: two compartments, two identical copies of your document. INPI kept one, you kept the other. Modest cost, recognized evidential value. But a paper-only format, limited to 7 pages per compartment.

e-Soleau (since 2016)

The digital version, modernized in 2024 with a new portal. It accepts files up to 2 GB, at EUR 15 for 5 years (renewable up to 20 years). A recognized institutional solution.

The limits of e-Soleau

The proof depends entirely on INPI: you cannot verify it independently. Storage is time-limited (5 years, renewable but paid). And INPI remains focused on industrial property — patents, trademarks, designs and models — with heavy and expensive procedures for other needs.

Comparison ETcH vs e-Soleau / INPI
ETcHe-Soleau / INPI
StatusActiveActive (e-Soleau) / Patents
CostEUR 2EUR 15 / EUR 600+
DelayImmediate24-48h / Several months
FormatAny digital fileAny file, max 2 GB / Formal dossier
RenewalNot requiredEvery 5 years (max 20 years) / Annual fees
Target audienceIndividual creatorsCreators / Businesses
Independent verification

What INPI does well

  • Recognized institution, established case law
  • Strong legal protection for patents and trademarks
  • Point of contact in case of commercial disputes

Limitations for individual creators

  • e-Soleau costs EUR 15 with a duration limited to 5 years (renewable)
  • Patents protect technical inventions, not creative works
  • Design registration (EUR 250+) targets industrial product appearance
  • Procedures designed for businesses with legal budgets

Why ETcH takes over

ETcH is not meant to replace a patent. It's a different tool, for a different need: proving that a file existed at a given date, simply and affordably.

  1. You upload your file (any format)
  2. ETcH computes its digital fingerprint (SHA-256 hash)
  3. This fingerprint is anchored on the Ethereum blockchain
  4. You receive a certificate with everything needed to verify the proof — independently of ETcH

No renewal, no subscription. The proof is recorded in a public, immutable ledger. And verification is free — for you, for a court, forever.

Who is ETcH for?

  • Authors who want to timestamp their manuscripts at every stage
  • Designers, illustrators, photographers documenting their process
  • Independent developers protecting their source code
  • Musicians, composers, content creators
  • Researchers who want to date their work before publication
  • Anyone who creates and wants an objective record

INPI remains the reference for industrial property, and e-Soleau is a recognized solution for proof of prior existence. But its limited duration, higher cost, and the inability to verify proof independently leave a gap. ETcH fills it with a permanent, transparent, and affordable approach.