RELATED APPLICATIONS 
     This application is a division of application Ser. No. 10/287,104, filed Nov. 4. 2002 pending, which is a continuation-in-part of Ser. No. 10/237,348, filed on Sep. 6, 2002, now U.S. Pat. No. 6,596,118, issued Jul. 22, 2003, which is a division of Ser. No. 09/805,514 filed Mar. 13, 2001, now U.S. Pat. No. 6,521,322, issued Feb. 18, 2003, and is related to U.S. Pat. No. 6,544,629, issued Apr. 8, 2003. 
    
    
     FIELD OF THE INVENTION 
     The invention relates to a food package insert and more particularly to a multi-part insert containing a decoder game for food packages and methods for making the inserts. 
     BACKGROUND 
     Inserts for food packages have been used for a number of years for promotional and entertainment purposes, e.g. game pieces, prizes and the like. In order to protect food in the packages from contamination from the inserts, the inserts are typically sealed in an impervious film envelope, e.g., the inserts are over-wrapped with a protective barrier film. The barrier film not only protects the food from contamination but also reduces the absorption of oil, grease and/or moisture from the food which can soil or damage a printed insert. However, over-wrapping the insert is a secondary, independent process that is conducted after printing the insert. Accordingly, over-wrapping adds costs and time to provide a finished over-wrapped insert product. 
     Because of the over-wrapping, the insert must be smaller so that the overall over-wrapped insert meets particular size criteria. In some cases, the over-wrapping is damaged or not properly sealed thereby leading to damage of the insert. Another problem with over-wrapped inserts is that the over-wrapping may pose a choking hazard for small children. The plastic over-wrap is typically not water soluble and if ingested by a child may cause injury or death. 
     Accordingly, there is a need for inserts for food packages which are safe for children and which can be produced in high volume with a relatively low cost. There is also a need for a method for producing game or prize inserts for food packages which will not contaminate the food and are not soiled by the food itself. 
     SUMMARY OF THE INVENTION 
     With regard to the foregoing and other objects and advantages, the invention provides a food package insert comprising a multi-part, in-line produced structure having at least one removable edge portion along a first edge thereof and a second edge portion opposite the removable edge portion. The multi-part structure includes an oil and grease resistant cellulosic support web having first and second exterior surfaces, first and second facing interior surfaces, and a support web edge portion disposed adjacent the removable edge portion thereof. At least one hidden image is imprinted on one of the first and second facing interior surfaces, the hidden image being is printed in a first color and having a second color imprinted over the first color in a pattern sufficient to substantially hide the hidden image. A colored film insert is attached to the fixed edge portion of the support web between the facing first and second interior surfaces thereof. The colored film insert is printed with the second color and is at least partially transparent for revealing the hidden image printed on one of the first and second interior surfaces. The first and second exterior surfaces, first and second interior surfaces, and multicolored film insert are printed by an in-line printing process. 
     In another aspect, the invention provides a method for making a method for making a food safe food package insert having multiple parts. Each insert has at least one removable edge portion on a first edge thereof and a second edge portion opposite the removable edge portion. The method includes the steps of providing a first cellulosic support web having at least one removable edge portion on a first edge thereof, a second edge portion on a second edge thereof opposite the first edge, a first inner surface, and a first outer surface. At least a first color is printed on one surface of a polymeric film by an in-line printing process so that the polymeric film remains partially transparent. The polymeric film has at least one removable edge portion on a first edge thereof, and a second edge portion on a second edge thereof opposite the first edge. A second cellulosic support web having at least one removable edge portion on a first edge thereof, a second edge portion on a second edge thereof opposite the first edge, a second inner surface, and a second outer surface is provided. An image is printed using a second color on one of the first and second inner surfaces and first and second outer surfaces of the first and second cellulosic webs by an in-line printing process. The image is overprinted with the first color in a pattern sufficient to provide a substantially hidden image. The film is disposed between the first cellulosic support web and the second cellulosic support web. The first edge portion and the second edge portion of the first support web, second support web and polymeric film are attached to one another to provide the multiple part food package insert. 
     An important advantage of the food package insert of the invention is that the entire assembly is made of cellulosic materials, food grade inks and adhesives. Another advantage is that the insert may be made of completely water soluble materials without the need for over-wrapping or placing the insert in an impervious envelope. This feature enables a plurality of inserts to be made from an elongate web and detached from the elongate web at the point the inserts are place in food containers. Accordingly, the entire process for making the elongate webs containing decoder game pieces may be provided by a continuous printing and assembling unit. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     Further advantages of the invention will become apparent by reference to the detailed description when considered in conjunction with the figures, which are not to scale, wherein like reference numbers indicate like elements through the several views, and wherein: 
     FIG. 1 is an exploded view of an insert made according to the invention; 
     FIG. 2 is a side-elevational view of an insert made according to the invention; 
     FIG. 3A is a plan view of an insert made according to the invention with a removable edge portion; 
     FIG. 3B is a plan view of an insert according to the invention with a removable edge portion partially removed; 
     FIG. 3C is a perspective view of an insert according to the invention partially opened to expose an inner film layer; 
     FIG. 4 is a plan view of a of an inner film layer according to the invention; 
     FIG. 5 is a plan view of a hidden image section of an insert according to the invention; 
     FIG. 6 is a plan view of a hidden image section of an insert showing a hidden image according to the invention; and 
     FIG. 7 is a schematic view of a process for making an insert according to the invention. 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     With initial reference to FIGS. 1 and 2, a food insert according to the invention is provided by a multi-layered structure  10  including a first cellulosic support web  12  and a second cellulosic support web  14  preferably made of oil and grease resistant (OGR) webs. The first support web  12  has a first surface  16  and a second surface  18  opposite the first surface  16 . At least one removable edge portion  20  is provided on a first edge  22  of the first support web  12  and second edge portion  24  is disposed opposite the removable edge portion  22 . The second edge portion  24  may be a fixed edge portion or a removable edge portion of the multi-layered structure  10 . 
     Likewise, the second support web  14  has a first surface  26  and a second surface  28  opposite the first surface  26 . The at least one removable edge portion  20  is provided on a first edge  30  of the second support web  14  and second edge portion  24  is disposed opposite the removable edge portion  20 . The second edge portion  24  may be a fixed edge portion or a removable edge portion of the multi-layered structure  10 . 
     The first and second support webs  12  and  14  are preferably provided by a relatively heavy weight paper or paperboard material which is treated so as to be substantially oil and grease resistant and is approved for direct food contact. For the purposes described herein, the support webs  12  and  14  cannot be treated with chemicals which are leachable from the web and are harmful if ingested. Particularly preferred support webs  12  and  14  include a 50 pound per ream OGR web made by Badger Paper Mills, Inc. of Peshtigo, Wis. The oil and grease resistance of the support webs  12  and  14  may be provided by incorporating suitable chemicals in the web during manufacture of the webs  12  and  14  or by applying a layer of oil and grease resistant material, such as polypropylene to the second surfaces  18  and  28  of the support webs. 
     The first surfaces  18  and  28  of the support webs  12  and  14 , are preferably printed with non-toxic inks suitable for direct food contact. The non-toxic inks are preferably water soluble inks which exhibit excellent adhesion and abrasion resistance when applied to cellulosic webs and to medium, low or high density treated polyethylene, polypropylene, cellophane, foils and the like. Such inks are available from Colorcon, Inc. of West Point, Pa. under the trade name NT-23. 
     The second surfaces  16  and  26  of the support webs  12  and  14  and a polymeric film  32  disposed between the first and second web  12  and  14  may also be printed with inks which are suitable for indirect food contact. Such inks are also preferably non-toxic inks which are sanctioned by the Food &amp; Drug Administration (FDA) and the United States Department of Agriculture (USDA) as acceptable for minimal food contact applications. The inks are water-based and comply with Environmental Protection Agency (EPA) regulations. Such inks may be applied to the surfaces  18  and  46  by flexographic and gravure printers and are available from Colorcon, Inc. under the trade name FLEXICRAFT. 
     The adhesive used to attach the support webs  12  and  14  and the film  32  to one another along the removable edge portion  20  and the fixed or removable edge portion  24  of the multi-layered structure  10  is preferably a low odor adhesive suitable for indirect food contact. Such adhesives are preferably aqueous adhesives based upon ethylene/vinyl acetate emulsions, polyvinyl alcohols, acrylic and polyurethane dispersions and emulsions available from Croda Adhesives, Inc. of Itasca, Ill. under the trade name CRODAFIX 57-174. The adhesive is preferably applied only in the edge portions  20  and  24  of the multi-layered structure  10 . However, for applications requiring the multilayered structure to be inserted in a salty food snack such as potato chips and the like, it is desirable to also apply the adhesive adjacent opposing side edge portions  34  and  36  of the multi-layered structure  10 , so that the interior surfaces  16  and  26  and film  32  are sealed on all four edge portions from the food contact. 
     With reference to FIGS. 3A and 3B, the removable edge portion  20  is preferably separable from a main portion  38  of the multi-layered structure  10  by is perforated seam  40 . A partially removed edge portion  20  is illustrated in FIG.  3 B. Any perforations suitable for aiding separation of the edge portion  20  from the main portion  38  may be used. It will be recognized that a perforated seam such as seam  40  may also be used for edge portion  24  in the instance where edge portion  24  is also a removable edge portion rather than a fixed edge portion. 
     A particularly important feature of the invention are perforations  42  and  44  on the opposing side edge portions  34  and  36 , respectively. Perforations  42  and  44  are disposed in an elongate multi-layered web to provide individual inserts  10 . The perforations  42  and  44  enable the inserts  10  to be separated from one another during a food package insertion process described in more detail below. The perforations  42  and  44  must be sufficient to hold individual inserts  10  together in an elongate multi-layered web, yet the inserts  10  must be readily separable from one another for automatic placement of the inserts  10  in a food package. Accordingly, the burst strength or tensile strength of the perforations  42  and  44  is preferably in the range of from about 6 to about 16 pounds per lineal inch of perforations  42  and  44  on opposing side edge portions  34  and  36 . The burst strength of a line of perforations is generally determined by the ratio of cut and tie of a perforation in the line of perforations, by the sharpness of the perforating blade or wheel, the pressure of the perforator, and the paper quality. A particularly preferred perforation  42  or  44  is known as a castle perf. The cut of the perforating blade for such a castle perf preferably ranges from about 0.05 to about 0.09 inches and the tie of the castle perf preferably ranges from about 0.04 to about 0.08 inches. A particularly preferred castle perf has a cut of 0.0781 inches and a tie of 0.0625 inches. To meet the desired burst strength based on the tensile strength of the substrate, a shim is added between the perf blades. The shim preferably has a thickness ranging from a bout 0.001 to about 0.002 inches. Opposing edge portions  34  and  36  may contain adhesives such as food grade pressure sensitive adhesives between the layers of the multi-layered structure in order to provide enhanced protection of the printed images and foods. 
     Once the removable edge portion  20  is completely removed from the structure  10 , the inner film  32  is exposed as shown in FIG.  3 C. The inner film  32  is preferably made of a clear polyolefin film with a thickness of about 2 mils. The film  32  may be separate from the support webs  12  and  14  or may be attached to the edge portion  24 . It is particularly preferred that the film  32  be removably attached to the edge portion  24  so that the film  32  may be separated from the structure  10 . For decoder game, described below, the film  32  is preferably coated or printed with at least one color and preferably two different colors, a first color  46  and a second color  48  as shown in FIG.  4 . 
     A preferred use of the multi-layered structure  10  is as a game piece, preferably as decoder game piece containing a hidden image printed section  50 , used in conjunction with colored film  32  as illustrated in FIGS. 4-6. The hidden image printed section  50  preferably contains a visible image section  52  and one or more hidden image sections  54  and  56  printed on one or more of surfaces  16  and  26  of the first and second support webs  12  and  14 . Image sections  52 ,  54 , and  56  printed on surface  16  of web  12  are described for illustrative purposes. 
     In order to provide a decoder game piece, images  58  and/or  60  are printed on the surface  16  of the support web  12  in the hidden image area(s)  54  and  56 , respectively. The images  58  and  60  are preferably printed with the same color or a different color than the first and second colors  46  and  48  of the film  32 . For example, if the first color  46  of the film  32  is red, then image  58  is preferably printed with a color on the opposite side of the color spectrum from red, such as blue. Likewise, if the second color  48  of the film is blue, then the image  50  is preferably printed with a color such as yellow. An overprint having the same tint as the first and second colors  46  and  48  is then preferably applied over the images  58  and  60  to provide hidden images in hidden image sections  54  and  56  as shown in FIG.  5 . Applying the colored film  32  to the hidden image sections  54  and  56  provides viewing of the images  58  and  60  in these sections as shown in FIG.  6 . Hidden images may also be applied to surfaces  18  and  28  of the support webs  12  and  14  or to the outside of a food package containing the game pieces described above for decoding with film  32 . 
     With reference to FIG. 7, a method for making the multi-layered structure  10  for insertion in a food package will now be described. The multi-layered structure  10  is preferably formed from individual elongate webs  62 ,  64 , and  66  fed from feed rolls  70 ,  72  and  74 . Roll  70  provides the cellulosic support web  14 , roll  72  provides the polymeric film  32 , and roll  74  provides the support web  12 . Each of the webs  12 ,  14 , and  32  are processed through multiple printing units represented by rectangles  76 ,  78  and  80 . The printing units, for example, may include from one to sixteen units to apply black, cyan, magenta, yellow and/or opaque white inks to each side of the webs. The printing units represented by rectangle  76  provide printing to the first and second surfaces  26  and  28  of the support web  14 . The printing units represented by rectangle  78  provide printing to the first and second surfaces  16  and  18  of the support web  12 . The printing units represented by rectangle  80  provide printing to the polymeric film  32 . 
     Web  64  is also passed through an adhesive unit  82  which may be one or two printing units which apply adhesives to the opposing surfaces of web  64  in the removable edge portion  20  and opposing edge portion  24  of the polymeric film  32 . Adhesive units may also be used to apply adhesive to edge portions  20  and  24  on surfaces  16  and  26  of the support webs  12  and  14 . 
     Once the adhesive is applied to the edge portions  20  and  24 , the webs  62  and  66  are adhesively attached to the polymeric film  32  to provide an elongate composite web  84 . If desired, in order to improve the oil and grease resistance of the multi-layered structure  10  made from the composite web, a polymeric layer such as polypropylene may be applied to surfaces  18  and  28  of the support webs  12  and  14  by an extruder, printing unit or coater. The amount of a polymeric layer preferably ranges from about 0.05 to about 1.5 mils providing a polymeric layer thickness ranging from about 0.5 to about 1.5 mils. 
     After the composite web  84  is formed, with or without the polymeric layer, the composite web  84  is perforated in a perfing unit  86  to provide individualized food inserts which may be removed from the elongate composite web  84 . The perforated web  88  may then be rolled on a transfer roll  90  for transportation to a food packaging plant. 
     In the alternative, a perforated web  88  may be fed directly to an in-pack machine which separates individual inserts from the web  88  and disposes the inserts in a former funnel of a food package filling machine. Since the package filling machine and the printing units  76 ,  78  and  80 , adhesive unit  82 , and perfing unit  86  do not typically run at the same speed as the package filling machine, multiple package filling machines may be provided in line with the manufacture of the perforated web  88 . 
     In the food packaging machine, the insert is combined with food as food packages are being filled on a continuous basis. Accordingly, the insert of the invention is adaptable to a continuous operation which provides inserts from an elongate web  88  formed in a separate operation or in a separate location and inserts formed directly from the printing and perfing machines in the same location as the food packaging machine. Elimination of the over-wrapping step also provides an improved food package insert as described above thereby reducing operating and equipment costs for providing such inserts. 
     Having described various aspects and embodiments of the invention and several advantages thereof, it will be recognized by those of ordinary skills that the invention is susceptible to various modifications, substitutions and revisions within the spirit and scope of the appended claims.
A food package insert comprising a multi-part structure having at least one removable edge portion. The multi-part structure includes an oil and grease resistant cellulosic support web having first and second exterior surfaces, first and second facing interior surfaces, and a support web edge portion disposed adjacent the removable edge portion thereof. At least one hidden image is imprinted on one of the first and second facing interior surfaces. The hidden image is printed in a first color and a second color is imprinted over the first color in a pattern sufficient to substantially hide the hidden image. A colored film insert is attached to the fixed edge portion of the web between the facing first and second interior surfaces. The colored film insert is printed with the second color and is at least partially transparent for revealing a hidden image printed on one of the first and second interior surfaces.