IE48568B1 - Printing - Google Patents

Description

This invention relates to a method of printing and a printed article produced by such method.

It is for some purposes required temporarily to obscure printed information on an article in such a way that access to the information can only be had under certain circumstances. One example of such, a requirement arises in connection with lottery tickets, where the information which determines whether or not a ticket is a winning ticket is required to be concealed until after the the ticket has been purchased.

In a known process the information is printed on a non-absorbent surface and covered by a deposit of a latex which should adhere to the non-absorbent surface sufficiently to ensure that the deposit is not abraded away 15 away by normal handling, but can be removed relatively easily by intentional scraping with a sharp object, such as a coin.

However, as it is not always possible to ensure that the degree of adhesion is consistent, the latex may Occasionally be inadvertently removed and on other occasions it may be difficult to remove without detriment to the printed matter beneath. 8 5 68 Further, since removal of the latex gives direct access to the printed matter, it may be possible without undue difficulty to falsify the printed matter after removing the latex.

Patent Specification No. 46041 discloses a contest card in which the indicia are printed on one surface of a card stock material, an opaque sectionally removable mask overlies the indicia, and a patterned layer of material is positioned immediately above the indicia but beneath the opaque mask.

The present invention provides a method of printing wherein information which is to be temporarily obscured is printed on at least one face of a substrate, said face of the substrate at least in the region occupied by said information is sealed by the application of a liquid composition which sets to form an impervious tough film through which said information can be seen, and then there is deposited on said film in at least those areas corresponding to said information a layer of an effectively opaque substance which can subsequently be removed by abrasion without destroying the underlying film.

By interposing a tough film between the printed information and the deposited material, the risk of inadvertent damage to the printed information during removal of the obscuring layer is significantly reduced, and the possibility of deliberate falsification of the printed information is reduced.

Preferably, the substrate affords an absorbent surface at said face so as to make it still more difficult to falsify the printed information.

For the purpose of sealing the printed surface, it is possible to use a variety of commercially available varnishes or lacquers, which may be either colourless or preferably coloured and conveniently the opaque substance which is finally deposited on the film formed by such varnish or lacquer comprises an ink which can be 8 5θ8 applied by a conventional printing process, such as a silk screen process.

In this way, the three stages of the process may be carried out in a single, continuous operation on one machine, or a line of adjacent machines· Tlie invention also resides in a printed article when produced by the above method and consisting of a substrate having printed on at least one face thereof information which is temporarily obscured by means of an opaque substance deposited on a tough film formed on the face of the substrate by application thereto of a liquid composition which sets to form such film.

When the invention is applied to the production of lottery tickets, such tickets will normally be printed sheets including a large number of different tickets.

In a preferred embodiment of the present invention the information is printed on artboard which has an absorbent surface and the whole face of the board is coated with a varnish, or a mixture of varnish and ink, and thereafter appropriate areas of the surface are obscured by deposition of a suitable ink, for example a silver ink, preferably by a silk screen process.

The invention will now be described by way of example with reference to oiie specific process and product as illustrated in the accompany drawing.

In accordance with the invention, a sheet of lottery tickets is formed by passing a continuous web of artboard through a succession of stations Λ,Β and C at which the following operations arc performed on the web.

Firstly, at station A, printing ink 11 is applied to the artboard 10 by means of a conventional printing process.

It will be understood that at this stage the whole of the information which it is desired to print on the upper face of the artboard 10 is applied. This may include areas of information as illustrated at 11 which it is desired to obscure temporarily, and also other areas of information (not shown) which are not to be obscured.

The printing may comprise a single stage printing or a number of sequential printing operations in differing colours, At station B, a liquid composition 12 consisting of a mixture of a varnish and a printing ink is applied to the upper face of the artboard 10. This composition dries to form a tough, impervious, but transparent film 13 through which the printed material 11 can clearly he seen. In tills way, the printed information 11 is secured so that it cannot readily be tampered with. Also, since tho artboard 10 has a porous surface, the ink applied thereto also defuses someway into the thickness of the web so as to afford additional security.

As the web passes through station C, an obscuring layer 14 of a suitable printing ink is applied hy any suitable conventional printing process in areas corresponding to the printed information 11 which it is desired to obscure temporarily. We have found that a particularly suitable ink for this purpose is a silver ink available from Coats Brothel's Inks Limited, under tho designation K4273. This has a sufficient degree of opacity and adheres to tho film 13 to a degree sufficient to withstand normal handling, whilst allowing easy removal by scraping.

After completion of the three operations, the printed sheet is divided into individual tickets.

Any attempt to falsify the tickets can readily be determined because the film 13 will have to be disrupted in order to obtain access to the printed information 11o Since the coloured film 13 masks the whole surface of the ticket, any breach of the film will immediately be visible as a different coloured area where the true colour of tho board 10 is exposed to view. The whole film 13 cannot readily be removed from the board 10, since it is applied in liquid form and is absorbed into the pores of the absorbent surface, so that if the film is, in whole or in part, stripped away from the board 10, the surface of tlie board will be disrupted.

Claims (8)

1. A method of printing wherein information which is to be temporarily obscured is printed on at least one face of the substrate, said face of the substrate at least in the region occupied by said information is sealed by the application of a liquid composition which sets to form an impervious tough film through which said information can be seen, and then there is deposited on said film in at least those areas corresponding to said information a layer of an effectively opaque substance which can subsequently be removed by abrasion without destroying the underlying film.

2. A method according to Claim 1 wherein the substrate affords an absorbent surface at said face so that printing ink deposited thereon is absorbed into the subs trate.

3. A method according to Claim 1 or Claim 2 wherein the liquid composttion comprises a varnish or lacquer which is coloured, A. A method according to Claim 3 wherein the liquid composition comprises a mixture of varnish and an ink.

4. 5. A method according to any one of the preceding claims wherein tlie opaque substance comprises an ink which is applied by a conventional, printing process.

5. 6. A method according to any one of the preceding claims wherein the liquid composition is applied over the whole of said face and said opaque substance is confined to specific areas so that only selected printed information is obscured (Jloi’eby.

6. 7. Λ printed article produced in accordance wlt]i tho method as claimed in any one of the preceding claims and comprising a substrate having printed on at least one 5 face thereof information which is temporarily obscured by means of an opaque substance deposited on a tough film formed on the face of the substrate by application thereto of a liquid composition which sets to form such film.

7.

8. A printed article substantially as herein described with reference to the accompanying drawing.