The Soleau envelope, named after its French inventor, is a sealed envelope serving as proof of priority for inventions valid in France, exclusively to precisely ascertain the date of either an invention, idea or creation of a work. It can be applied for at the French National Industrial Property Institute (INPI). The working principles were defined in the ruling of May 9, 1986, published in the Official gazette of June 6, 1986 (Journal Officiel de la République Française or JORF), although the institution of the Soleau envelope dates back to 1915.
The envelope has two compartments which must each contain the identical version of the element for which registration is sought. The INPI laser-marks some parts of the envelope for the sake of delivery date authentication and sends one of the compartments back to the original depositary who submitted the envelope.
The originator must keep his or her part of the envelope sealed except in case of litigation. The deposit can be made at the INPI, by airmail, or at the INPI's regional subsidiaries. The envelope is kept for a period of five years, and the term can be renewed once.
The envelope may not contain any hard element such as cardboard, rubber, computer disks, leather, staples, or pins. Each compartment can only contain up to 7 A4-size paper sheets, with a maximum of 5 millimetres (0.2 in) thickness. If the envelope is deemed inadmissible, it is sent back to the depositary at his or her own expense.
Also, unlike a patent or utility model, the depositor has no exclusivity right over the claimed element. The Soleau envelope, as compared to a later patent, only allows use of the technique, rather than ownership, and multiple people might submit envelopes to support separate similar use, before a patent is later granted to restrict application.
In case of an invention, the envelope only constitutes proof that the depository knew the invention before any patent application at the INPI or at the European Patent Office for the French territory, and allows him or her to continue exploiting the invention. Personal exploitation is practically very restrictive and can't be licensed to third parties. It is only valid for the French jurisdiction and intends to assert a date of creation, not to protect an invention, idea or work.[original research?]
- Stephen Pericles Ladas, "Patents, trademarks, and related rights: national and international protection", Volume 3, Harvard University Press, 1975, p. 864, referring, in footnote 118 to: "On the French law and the institution of the Soleau envelope, see Prop. Ind. (1915), pp. 103 ff.
- (French) INPI web site, User's guide to the enveloppe Soleau
- (French) INPI web site, The life of an enveloppe Soleau