1 METHOD OF PRODUCING HARD WEARING SIGNAGE FIELD OF THE INVENTION 5 This invention relates to signage and in particular to methods of producing signs on surfaces which are subject to wear and tear. BACKGROUND OF THE INVENTION 10 Adequate safety signage is important in many industries to warn of potential hazards, restrict access or to provide safety directions. Traditionally, safety signs have been constructed of metal with ink or paint applied to the surface. Such signs, when used in industrial or outdoor environments, are subject to wear and damage causing warning statements to fade. This is not only dangerous but 15 costly to business and property owners who must constantly replace worn signage. Protective coatings have been used in an attempt to prevent damage of printed signage. For example, US 7,184,068 B2 teaches a method of thermal transfer 20 printing of labels onto a polyethylene terephthalate (PET) carrier ribbon. An adhesive is laminated onto the PET film over the printed image and used to attach the label to a surface while the PET film protects the printing from environmental damage. 25 US 5225260 teaches a method of reverse printing a large scale sign onto a polyvinyl fluoride film and applying a layer of adhesive over the printing. Using several layers of carrier, application, transfer and adhesive tape the sign can be attached to a surface with the polyvinyl fluoride film facing outwards thereby protecting the printed sign underneath. 30 In darker working environments, such as in mines, it is necessary to have highly reflective signage to ensure visibility of the sign in limited lighting. Although there 2 are reflective paints available, reflective signage is commonly made using reflective sheeting with glass beads or specialised microprisms which is more effective and provides up to 60% reflectivity of available light. 5 The surface of such reflective sheeting can be damaged during construction of the sign or during daily use resulting in deterioration of its reflectivity. Current methods used in an attempt to protect reflective signage include that described in CN 201259556 (Y) which provides a reflecting film for traffic safety signs comprising the following layers: a signage layer, a focusing layer, a layer of glass 10 beads, a layer of polyester resin, a polyvinyl chloride (PVC) resin layer and a protective transparent PET film layer. This method is complicated and requires the application and drying of several liquid layers which can take significant time and can be expensive. 15 GB 2247859 teaches a sign which comprises a rear plastic film adhered to a fabric material having reflective beads to provide a reflective surface and a thin plastic protective film over the reflective material. This sign is very thin and may sag, warp or be easily damaged in an industrial or outdoor environment. 20 OBJECT OF THE INVENTION It is therefore an object of the present invention to provide a method of producing signage that is hard wearing and reflective or at least to provide an alternative to the prior art. 25 3 STATEMENT OF THE INVENTION According to the present invention a method of producing a hard wearing sign comprises reverse printing an image onto a surface of a transparent plastic panel 5 said image having spaces therein, cutting reflective sheeting to substantially the same size as said spaces and attaching cut reflective sheeting to said surface of the transparent plastic panel the reflective surface of which can be seen through spaces in said printed image, applying a double-sided adhesive to said surface of the transparent panel over the top of the printed image and reflective sheeting 10 and adhering said double sided adhesive to a supporting structure. Alternatively, an additional layer of signage is applied behind the reflective sheeting. 15 Preferably, the double sided adhesive is a clear, pressure sensitive, acrylic or high bond adhesive. Preferably the supporting structure is a flat or slightly curved surface. 20 Alternatively, bolts or hooks are used to secure larger signs to the supporting structure or to secure signs to an uneven or angled supporting structure. BRIEF DESCRIPTION OF THE DRAWINGS 25 An embodiment of the invention is now described by way of example only with reference to the accompanying drawings in which: Fig 1 is a perspective view from below of a reverse printed image on a transparent plastic panel. 30 Fig 2 shows reflective lettering applied to the back of a sign. Fig 3 also shows reflective lettering applied to the back of a sign. Fig 4 shows the removal of the backing layer of a sign revealing a layer of adhesive.
4 Fig 5 shows an additional layer of signage being applied to the underside of a sign over the top of a reverse printed image and reflective lettering. DETAILED DESCRIPTION OF THE INVENTION 5 In a preferred embodiment of the present invention an image 1 is reverse printed onto the back of a transparent plastic panel 2, such as polyvinyl chloride (PVC), as shown in Fig 1. Image 1 is reverse printed so that when viewed through the transparent panel 2 it appears in normal view. Image 1 may be a single matt 10 colour or may be semi translucent or patterned and could include text, shapes or photographs. The areas of the sign that are to be reflective will not be printed and will remain transparent spaces 3. High quality reflective sheeting 4, such as 3M DG , is prepared in shapes 15 corresponding to the unprinted areas of the sign 3 as shown in Fig 2. A pressure sensitive, double-sided adhesive film 5 with a removable backing (not shown) is applied to the front of reflective sheeting 4. Adhesive film 5 is a clear, acrylic or other high bond adhesive. 20 The removable backing of adhesive 5 is pulled away and reflective sheeting 4 is adhered to the back of panel 2 covering unprinted areas 3 as shown in Fig 2. Reflective sheeting 4 is cut to slightly larger dimensions than unprinted areas 3 of panel 2 to ensure coverage of all transparent sections 3 as shown in Fig 3. 25 Another layer of adhesive film 5 is applied to the entire back surface of panel 2 over the top of printed image 1 and reflective sheeting 4 as shown in Fig 4. To install the finished sign backing 6 is removed exposing adhesive 5 which is pressed against a supporting structure thereby securing the sign in place. 30 Printed image 1 and reflective sheeting 4 are underneath transparent panel 2 and are protected by transparent panel 2. The sign can be applied to any flat, porous 5 or non-porous structural surface including metal, paint, concrete, plastic or glass. The sign is flexible and may also be applied to gently curving surfaces. In an alternative embodiment of the present invention an additional layer 7 may 5 be adhered behind reflective sheeting 4, as shown in Fig 5, creating a layered effect or a perception of depth in the sign. Layer 7 may be a further plastic panel, a vinyl sheet or other block out film. Accordingly a further layer of adhesive 5 is required to attach the sign to a surface. In yet another embodiment of the present invention no image is printed onto the transparent panel so that the sign has only 10 reflective sheeting 4 and the background signage layer 7 applied to transparent panel 2. ADVANTAGES 15 The present invention provides a method for producing high visibility signage that is hard wearing. The present method extends the life of reflective signage thereby reducing the safety risks and maintenance costs involved with damaged or unseen safety signage. 20 Furthermore, the method allows for greater variation in the image that can be printed onto the sign and provides for multiple image layers creating a more aesthetic and visually pleasing sign. VARIATIONS 25 It will be realized that the foregoing has been given by way of illustrative example only and that all other modifications and variations as would be apparent to persons skilled in the art are deemed to fall within the broad scope and ambit of the invention as herein set forth. It will be obvious to one skilled in the art that in 30 certain circumstances bolts or hooks may be required to secure larger signs to a supporting structure to secure signs to an uneven or angled structure 6 Throughout the description and claims of this specification the words "comprise" and variations of that word such as "comprises" and "comprising" are not intended to exclude other additives components integers or steps. 5