Genuine lithograph or print? How to date a poster

A genuine lithographic poster from the 1890s is printed with one stone for each colour: the colours lie in opaque layers, the surface has a fine grain and the registration is often slightly out. A modern print consists instead of small dots in four colours, clearly visible under a magnifying glass. The poster’s size, the paper, the printer’s name in the margin and traces of folding then help to tell an original from a later edition or reproduction.

Facts

Stone by stone

Lithography is based on grease and water repelling each other. The artist draws with greasy crayon or tusche on a ground limestone, the stone is dampened and inked, and the ink sticks only where the drawing is. A colour poster needs a stone for each colour, and the sheet is printed again and again, from the lightest colour to the darkest. How this works is shown by the diagram Colour lithography, stone by stone below and by the guide to printmaking techniques.

Jules Chéret created the modern colour poster in Paris with large lithographs from the 1860s and 70s, such as Orphée aux enfers of 1858 and Bal au Moulin Rouge of 1889. In the 1890s came Toulouse-Lautrec, Alphonse Mucha and Pierre Bonnard, and even then the posters were collected by a large public.

What the magnifying glass shows

The surest test is a magnifying glass. In a lithograph the colour lies in even or grainy fields with soft edges, and where two colours overlap they blend into a third. The grain comes from the surface of the stone or from the crayon and is irregular. A large area of the same tone may also be stippled with a hand-made pattern of spatter or grain, but never in a regular grid.

An offset print or a digital print is instead built up from halftone dots in cyan, magenta, yellow and black, arranged in rows and angles that form small rosettes. The screen is clearly visible at ten times magnification, even where the image looks smooth from a distance. A poster with halftone dots can be old – halftone printing was already used around 1900 – but a poster claimed to be a Mucha from 1896 should not have them.

Registration, signature and printer

Because each stone was printed separately, the colours seldom land exactly on top of one another. Small gaps at the edges, colours that extend a millimetre beyond the outline and sometimes registration marks in the margin are signs of a genuine stone print. A perfectly registered print without the slightest gap is suspect.

The artist’s signature is printed in the image itself, not written by hand, and the printer’s name and address appear in small type in the margin. Chéret worked with the printer Chaix and Mucha with Champenois in Paris. On the poster for JOB and on Gismonda the signature is visible in the image. Reproductions have often had the printer’s text trimmed away or replaced with a modern publisher’s name.

Paper, format and folding

Original posters were printed on cheap, thin paper that was meant to stay on a wall for a few weeks. The paper has often yellowed, and many originals were folded to be posted or stored and later mounted on linen by a conservator to preserve them. Fold marks and a linen backing are therefore common on genuine posters and rare on reproductions.

The format also tells you something. Many 1890s posters were large, over a metre high, and were sometimes printed on two sheets. The same design was often issued in smaller formats for collectors, and those editions are genuine lithographs from the same period. Modern reproductions often have a standard format, white, thick paper and a glossy surface.

From lithography to offset

In the 20th century other techniques took over. The flat colour fields of the Sachplakat and the airbrush of the 1930s were still often printed lithographically, but after the Second World War offset became the usual technique, and screen printing gave Pop Art its bold colours. The question whether a poster from the 1960s is a lithograph is therefore usually the wrong question: it should be offset or screen print.

Date a poster, therefore, by the technique, the design and the text together. The lettering, addresses and prices on the poster belong to their time, and a poster for an exhibition or performance often has a date in the text. See more examples in the posters category, from Chéret to the 1970s.

How to recognise it

Exercise

Under the magnifying glass, a Mucha poster consists of small dots in rows, in cyan, magenta, yellow and black. What is it probably?