Abstract: An insert strip which is detachably insertable into a receiver strip so as to form a plate shelf to retain the side walls of the plate glass panels of a lampshade. A lower support which has a retainer ridge which conforms to the shape of the lower wall of the plate glass panel and retains the plate glass panel therein. The lower support also has a catch on either end thereof which fits into and is retained by catch holes on an injection plate. The injection plate also has an insert strip cavity and retainer walls which retain the insert strip and the receiver strip, respectively.