Type 6.02 The Geneva stamp was used from 1.VII. 1902 to 20.XI.1919.

The Cancellers of Frédéric de Coppet There are the great inventors that everyone knows like Edison or Reis; in philately only the findings of others have mostly been applied. But there are some special cancellers - and who invented it? Of course, two Swiss pioneers! First J.J. Güller had the idea to incorporate little wheels for the date and hour display instead of separate slugs that had to be replaced every hour and that could get lost. And in 1889 a teacher from Lausanne, Mr. Frédéric de Coppet, annoyed about the constant forearm discomfort of his friend at the post office caused by stamping, invented a canceller with a flexible head. From his first prototype to large-scale use it took 13 years. In October 1898, the Swiss PTT decided to test the new canceller. In order to easily distinguish those postmarks from the usual ones, they got an individual look with rounded corners in the bridge so resembling the outline of an old razor blade. And so the postmarks came to their special name "razor blade postmarks".

Rectangular Date Box

Forerunners for Lausanne, Bern and Ste. Croix
Delivery of the first test models to Bern 18 Sept. 1889.
Delivery of the first test models to Lausanne 18 Sept. 1889.
The trial canceller for Ste. Croix followed in 1 Jun. 1897.

These cancellers were produced after the first major test period. Due to their design with rectangular date and time boxes they are not "razor blades", however, they are part of the development of Coppet´s cancellers.
Exhibition postmarks of Bern 1900; Basel and Vevey 1901
25 Years of UPU - Bern 1900
Trade Fair - Basel 1901 and 1921
Trade Fair - Vevey 1901

Razor Blade Postmarks

Flexible hand stamp according to de Coppet

District	Office	Canton
I	Geneve	GE
II	Lausanne	VD
III	Bern	BE
IV	Neuchâtel	NE
V	Basel	BS
VI	Aarau	AG
VII	Luzern	LU
VIII	Zürich	ZH
IX	St. Gallen	SG
X	Chur	GR
XI	Bellinzona	TI

The post office asked de Coppet to prove that his cancellers could be mass pro- duced. Up to this time they had been individually hand made. De Coppet suc- cessfully presented four devixes and an additional design sdudy for Lausanne as prototypes leading to the contract being signed on 16 April 1903.
De Coppet cancellers with Bridge - late 1902
BASEL 2 -⟨⟩- FIL. B.B. -⟨⟩-	File:Razor blade stamp of Switzerland ?.jpg Is in processing
CHAUX-DE-FONDS • SUCC. LETT. •	File:Razor blade stamp of Switzerland ?.jpg Is in processing
GRENCHEN • SOLTHURN •	File:Razor blade stamp of Switzerland ?.jpg Is in processing
ST MORITZ-DORF +	File:Razor blade stamp of Switzerland ?.jpg Is in processing
LAUSANNE -⟨⟩- BARRE-CITE -⟨⟩-	File:Razor blade stamp of Switzerland ?.jpg Is in processing
LAUSANNE + II -⟨⟩- BARRE-CITE -⟨⟩-	File:Razor blade stamp of Switzerland ?.jpg Is in processing

After the demonstration of the UPU commemorative postmark de Coppet was commissioned to produce two hand-stamps for the Post Office of Kristiania (now Oslo).
Cancellers for Kristiania (Norway), 1902
BUREAU REEXP. ♦ DE KRISTIANIA ♦	File:Razor blade stamp of Switzerland ?.jpg Is in processing
KRISTIANIA BREVPOST.	File:Razor blade stamp of Switzerland ?.jpg Is in processing

Excerpt from Handbook Swiss "Razor Blade Postmarks" 2015
Handbook of advertising date stamps Switzerland / Liechtenstein, Giovanni Balimann, Swiss Association of Postage Stamp Collectors SVPS

@ www.arge-schweiz.de/Seite-Links.html
@ www.zinken.net/deCoppet/inhalt.html
@ rogerheath.com/~thernsp2/roger/razorexhibit/1_page01.html