Identifying the difference between a lithograph and offset print – or how I spotted few forgeries on spanish stamps
I was preparing some scans on unwanted (duplicate or mint) items for my stamp exchange website when I noticed few mint Spanish stamps that didn’t seem to fit into picture. The subnotes on stamp catalog confirmed my hunch- I had stumpled upon forgeries of somewhat common and cheap stamps.
The original issues were printed using lithograph (”stone printing”), the forgeries were printed using offset. I know many collectors struggle with how to tell these apart - especially if having nothing to compare with. In reality the difference is quite easy to spot if you know what to look for:
What offset usually means (especially post 1920’s stamps) is photogravure print, and it will ALWAYS show lines of dots (or beads) of color when looked at proper (at least 10x) magnification. The dots will be visible on both the outlines and fills.
Lithograph print on the other hand will ALWAYS have a somewhat solid outline and fill. In lithograph, the paper is flat and there will be no notable indentations differentiating design from non-printed areas (except maybe on the top).
However, if you feel the printed design from the back of the stamp, then the stamp is printed in typography (also known as letterpress).
Below are some images to tell the difference using visuals between lithograph and offset (photogravure) print.
First, here’s a real spanish stamp printed in litho. Notice how firm the borders and fills are.
Lithography - borders and fills are clear + solid. No dot pattern visible.
And then a forgery printed in offset (photogravure). The print is very unclear and there is a visible dot pattern especially on outlines.
Offset - the print is somewhat unclear and there is always a somewhat visible dot pattern.
Instead of going to trade, the forgeries ended up into my collection.
Knowledge is power!
You might also be interested of related posts about Forgeries, Stamps and postal history of Spain (Espana).
Good eye Keijo!
Do you know how the dot pattern is created? Offset uses a rubber transfer plate/roller so I would expect it to be smooth. Is there a screen or mesh involved?
In modern offset printing (=photogravure), the dot-pattern is always there as image is build of very tiny dots with different colors (usually CMYK).
The image is etched using a photographic process (screening) onto the cylinder. This produces rows of dots, which make up the image. How visible the dots will be on final output, depends on (dot) density (which is usually 150 dots per inch or finer) and ink flow.
PS. I updated the original article a bit, as I know U.S. and European terminology of printing methods tend to be slightly different. This is especially confusing as different stamp catalogs use different (and sometimes even contradicting) names for same things.
Hi there.
I’m sorry to say I’m confused by your terms.
When looking at a stamp, why not imagine that there are 3 ways of getting the ink from a surface, which we can imagine as a landscape but printers call a plate, onto the paper? There is
1) pushing the tops of a hilly surface in- ink is on the tops and makes valleys, thus ‘letterpress’ oddly called ‘typo’ by stamp people, which abbreviated to T,
2) wiping the ink off the hilltops, leaving it in the valleys, which print as fine lines – engraved, intaglio or to us ‘recess’ and
3) landscape is completely smooth but grease on it repels ink in pattern of the design – lithographed.
In my experience ‘offset’ is when the plate prints to a rubber roller which then touches the paper.
‘Photogravure’ is related to engraving but we have pits of ink instead of valleys, the deeper ones for brighter colour tone.
Litho stamps may use dots to vary tone but it the diameter not the brightness that does the job. Letterpress also uses dots for varying tone in portraits, look at an old newspaper illustration. In stamps, look at Kishangarh, India. And lots of Indian states’ revenue stamps. Results are not good and nobody prints stamps by letterpress these days.
The book to find on this subject is Williams’ ‘Fundamentals of Philately’ but it’s long out of print.
Congratulations on your site- you have loads of energy and it’s great for the hobby.
Hi Peter,
I’m very familiar with how various printing methods work. But as said in response#2 the terminology (and naming) of printing methods (and how they are categorized) varies worldwide. For example as I’ve grown up with German Michel and French Yvert catalogues, the categorization and terminology used in this article is closest to me: http://www.bdph.de/kdb/fileadmin/PDF_Dateien/druck.pdf (8 pages, in german).
best,
-keijo-
Hi, nice site. But I don’t think your printing knowledge is as good as you say.
You say “In modern offset printing, the dot-pattern is always there”. That’s simply not true. (I’ll get to that.)
Wikipedia says photogravure produces a photo-engraving (like the name implies), not an offset plate.
Your authentic stamp is most likely produced by an engraved plate, not a lithograph.
Your fake has dots NOT because it is an offset print, but because it was printed using a half-tone screen.
A half-tone screen is used for gray-scale and full-colour images to reduce the colour intensity of the inks. In other words, to provide shading. You can’t change the shade of the ink, so you make the dots bigger or smaller.
In your fake there’s only one colour of ink, so the use of the half-tone screen says more about capturing the image of the stamp (on film or computer) than it does about the printing technology. If you tried capturing it as line art, you would have to spend a lot of time fixing glitches in the image. It’s easier to treat it as grey scale.
A dot pattern is NOT always there in modern offset printing. It’s used a lot, but that’s because it’s cheap and versatile. Using half-tone CMYK, you can do a pretty good job of reproducing most colours. It’s good enough for magazines and newspapers, but not good enough for many uses.
For product packaging, most companies will pay more money to print with specific ink colours. Solid colours will be printed solid (no dots) with precisely the colour chosen by the marketing department. Open up the bottom of a cereal box… There will usual be a grid showing all the colours of ink used to print the box. This may include CMYK, but will probably include other colours. A pepsi box may only use 4 colours: white, red and 2 shades of blue.
I suspect that the same is true for modern stamps. If there is an area of solid colour, it is probably solid (no dots) using a precise ink colour. You would get much better results this way.
Hi Bill,
I’m not a print worker, but I consider myself to know “enough” of various printing methods. That said, I don’t claim or expect to be correct 100% time (in which cases I usually keep my mouth shut and learn more)
Anyway, it seems we’re getting a nice debate with this topic (finally, LOL).
Like said in two replies above, we are talking about same things but with different terminology. “Stamp print terminology” used in US is more or less alien here in Europe – and vice versa. Same terms CAN mean different things (and it is without a doubt causing troubles).
So please read the document I linked in response above (or if German language provides difficulties, then you can read (a machine) translated version here )
For the stamp in picture (Spain, 1937/39 – Michel#770, Scott 644) all European catalogues I have state printing methods to be Stdr / Steindruck, which translates to lithography (or more precisely stone lithography; which is of course completely different thing than modern offset litho).
Scott (Classic Specialized) catalogue on the other hand states nothing about print method used (leaving out also lots of other details mentioned in European stamp catalogs).
To quote original post: “What offset usually means (especially post 1920’s stamps) is photogravure print…”. And once again this is in “European stamp catalogues context”.
Unlike half-tone processes which just vary the size of dots, in photogravure also the quantity and depth of ink wells are varied. But dots are part of photogravure, always.
I am not as knowledgeable as any of you, so I was hoping someone could summarize concisely the following terms used in the Scott’s catalogs.
engr.
litho.
typo.
Any help with this would be greatly appreciated
Hi Rick,
these are all abbreviations Scott uses for various printing methods. See the preface of Scott catalog for proper description of these.
But shortly put I’d describe these as:
* In line engraved stamps the the ink is slightly raised (and it can be felt with fingertips) on image side.
* In litho the print is flat and the fine line detail of engraving is usually not present.
* In typography the lines and ink are debossed, and the pattern can be seen (and felt with fingertips) on the back of stamp.
Thanks very much, Keijo
A little vocabulary of terms adopted by Scott and Michel might be helpful:
Engraving ~ Stichtiefdruck
Typography ~ Buchdruck
Photogravure ~ Rastertiefdruck
Lithography ~ Offsetdruck oder Steindruck
Thanks! This article was exactly what I needed to properly identify a 1981 Australian 24c Tasmanian Tiger, which is apparently available in photogravure or lithography. I must remember to go through the duplicates again to make sure I don’t have the lithograph also!
Another excellent and useful article, Thank you Keijo!
@Toby… Thanks
We have been dealing with Photogravure vs Lithographed stamps in the long never ending Machin series (British Queen Elizabeth II stamps 1967 to date) for quite a few years.
We advise the collector to look either at the value borders or along the stamps outer color border.
Photogravure stamps have a ragged edge where the color lines meet the non-color areas.
Lithographed stamps have a more or less clean edge.
In fact, in many Photogravure issues, where it is important for the specialist to determine whether a stamp was printed from top to bottom or bottom to top, ( or even left to right instead or right to left,) to decide which printing is being examined, we look along the outer edges with a magnifier and can see the difference in the way the raggety edge is formed.
On Lithographed stamps the direction of printing can not be seen by examining the edges.
@Charlie… Thanks for sharing the advice / tip
@Charlie, Keijo
This past week, I’ve been going through trying to differentiate my Machins, following the general guidance you described above. I think I finally found one lithographed yesterday, (confirmed based on the perforations) but I’m uncertain. The edges and numerals are clean, but the bust looks composed of small dots. Is this typical of Machins? I’ve found scans showing the difference between the numerals in photo. and litho. machins on the Internet, but nothing showing a close up of the differences in the bust. I think I’m going to go blind looking at these through the magnifier… and I’m not even planning to keep any variations other than print type (i.e. phosphor tagging, etc)!
@ ….
Litho vs. photo on Machin stamps – I’m sure you have seen this: http://www.adminware.ca/machin/m_var.htm#Printing
I’m not a specialist with these, but I would rely on AdminWares statement “The easiest place to tell the difference between photogravure and lithographed stamps is in the denomination.”
I definitely do know what you mean with going blind with magnifier – I just spend few hours looking and identifying various inscriptions on Japanese prefecture / Furusato stamps.