How to distinguish between Originals & Forgeries.
Some History
A large number of deceptive forgeries seems to have been produced by René Carème of Paris, France. They were marketed by Lowden and Henry Revell Harmer of London, but also by the firms Westend Stamp Co. and Herbert Mack & Co Ltd. These forgeries were discovered around 1909. Around 2 million forged stamps were confiscated in Paris.
Fournier was thought to have made use of the printing plates from Careme.
However, Careme's creations were said to be of a better quality but in practice it is difficult to differentiate. Most of them are also pristine looking with full undisturbed gum. Genuine stamps very often have cracked gum. Also stamps with an irregularly thick Labuan type bar cancel are more likely to be from Carame.
These 2 were the main forgers but Spiro also contributed a rather crude forgery which is thought to account for 30% of collections.
Several other forgers were involved.
Genuines & Forgeries
These are either Careme or Fournier and represent the most dangerous forgeries.
1889 1/2 cent
Genuine
There is a constant dot right of the 1/2No dot besides the 1/2
Dash in top right letter between horizontal strokes.
The Careme cancel bars are too thick.
The bottpm left ornameny is too close to rhe frame
There is a large blank spot above the first hind leg
The "B" & "S" are the wrong dhape
NOTE single imperf stamps are almost always forgeries
1889 2 cents
In the genuineThese is a constant dot top left of the "N"
There is a constant dot near the border left of the "2"
A pair of Careme forgeries without genuine features
Lion has white appearance
There is a constant dot above the lower "N"
2 Careme forgeries missing both genuine features
There is a constant dot inside the lower left ornament frame
There is a small constant dot below the 2nd letter on the right
The legs of the "&" are the same length
The forgery is missing the dot and the bottom leg of the "&" is cut off shortThe legs of the "&" are the same length
There is a constant dot left of the bottom right letter
The tail of the "5" extends past the vertical stroke
5 end shorter and looking more normal
No dot besides 2nd letter right
Forgery
There is a constant dot in the top left ornament
The sail is curved but straight in the forgery
Missing top left dot and straight sail
1889 8 cents
There is a constant dot above the left lower frame line
The shaded inner does not touch the frame line
No dot and inner shading touches the frame line
Other Forgeries
Here is the most common which accounts for 30% of all collections
Rather rough and crude, it is attributed to Spiro
The full set of Spiro forgeries
Poddibly Oneglia