Several posts on this subject, so I thought I just pick one.
Quenvit, Quenoil ... several suggestions from different books etc... but I thought i'll share something that has been dug up on a different forum.
As mentioned earlier on, Quenvit was suggested bu Cappa. What I don't like about some parts of his books, is that he makes a very vague suggestion and then in the re-edition, he refers to himself in the earlier edition and makes the suggestion more or less a fact. He also does this with Verlux and Etling.
In 1991 he says about Quenvit "this unknown signature could probably be connected to Legras, as it, the signature, could be one of many variations". The illustrated vase is therefor attributed to Legras, but signed Quenvit.
In 1997 he says that the signature Quenvit can be linked to Legras because a vase looks very much like one from Legras. Ref edition Cappa 1991.
Hartmann says in the Glasmarken Lexicon, that it is a signature, that is often mistaken for Quenvit or Quenvil, but should be read as Quenoil. His reference comes from the 1930 Inventory of Ceramics and Glass manufacturers in France. The address of the mentioned company was 47, Rue d'Hauteville in Paris.
Unfortunately no Quenoil was ever registered there or ever existed, and I was surprised to read that, as Hartmann does refer to the inventory of 1930 having read Quenoil.
What was registered at this address, was a Henri Quenvil, glass and ceramics decorator. A clever person managed to find a couple of clippings in the online french library, dating back to 1919, 1923 and 1925.
One add is a demand for glass decorators from the newspaper 'Le Journal' 19 sept 1919, one from a listing in an industrial report from 1925 and one article from Le Figaro from 18 march 1923.
So I guess we can say this signature belongs to Henri Quenvil and not Quenvit or Quenoil.
What is also interesting, is that some books on Legras, say that Quenvil has got nothing to do with Legras, because the quality is far more superior then Quenvil, but at the same time, there was an outlet/department for Saint Denis Glass in the same street on number 62, so maybe as mentioned above, Legras produced blancs for Quenvil.