have been made accessible through the open areas of the photoresist layer 18 to take on a surface coating of the pigment powder which is retained by the adhesive properties of layer 16 to form the colored image areas 17 as shown at d at this stage in the processing the proofing sheet material appears as the positive duplicate of the color separation negative and is a sufficiently faithful reproduction of the negative to allow a qualitative examination for example of the formation of screening dots since some extraneous pigment powder will normally cling to the outer surface of the photoresist layer 18 however there may be some lack of true color discernment due to this 34 fogged 34 background should such a background coloration be of significant concern to the lithographer the remaining process steps may be effected to clear the background of the image exposure of the whole surface of the remaining photoresist layer to the actinic radiation renders that composition more soluble as at 13 in step e overall application of the developer solution then dissolves away the remaining photoresist layer to yield an imaged proofing sheet which consists essentially of the carrier sheet 12 having an overall layer of substantially transparent pressure sensitive adhesive 16 in which is imbedded the pigment powder image 17 as seen in processing step f in order to protect the powder image from the handling which will take place during a thorough proof examination a cover sheet of transparent film 19 may be applied over the surface of the imaged material to be retained in place by the accessible background of pressure sensitive adhesive layer 16 depending upon the type of carrier sheet initially utilized.