A process of manufacturing a bed covering system comprising the steps of: joining a lower sheet and a side panel assembly shaped to fit upon and substantially cover the top, sides and a portion of the underside of any mattress by stitching the side panel assembly to a peripheral edge of the lower sheet to form a lower layer assembly; forming zipper pocket layer assembly by cutting pocket layer panels (131, 132) to dimension, aligning attachment means (133, 134) along long edges of pocket layer panels (131, 132) in a predetermined location spaced apart from the top and bottom of the long edge of pocket layer panels (131, 132) and joining attachment means (133, 134) to pocket layer panels (131, 132) by sticking seam, thus forming side pocket panels (136,137); forming expansion panel assembly by cutting panels (141, 142) to dimension, aligning attachment means (143, 144) to panels (141, 142) and joining attachment means (142, 144) to panels (141, 142) by stitching seam thus forming expansion panels (148, 149); forming expansion layer assembly by aligning and subsequently joining the side pocket panels (136, 137) to the expansion panels (148, 149) by seam thus forming side expansion panel sections (103,152, 153);joining the lower layer assembly and an expansion layer assembly by stitching an edge of the side pocket panels (136,137) to an edge of the side panel assembly on opposite sides of the mattress; the side panel assembly configured to place the expansion panel (103, 152, 153) along a side of the mattress; joining an upper sheet to the expansion layer assembly so as to attach the expansion layer assembly to both the lower sheet and upper sheet; and joining at least one attachment means to the edge of the side panel (109, 110) and the upper sheet so as to allow opening and closing the bed covering system; joining edges of side panels assembly and side pocket panels (136,137) by stitching a corner seam to form elongated pockets to tuck the side expansion panel sections (103,152,153); joining a gathering means to the free edges of the side panel assembly by stitching the gathering means to the free edges and of the side panels (109, 110) and the other free edges of panels (123, 124, 125, 126) to join these and form a perimeter. joining a lower sheet and a side panel assembly shaped to fit upon and substantially cover the top, sides and a portion of the underside of any mattress by stitching the side panel assembly to a peripheral edge of the lower sheet to form a lower layer assembly; forming zipper pocket layer assembly by cutting pocket layer panels (131, 132) to dimension, aligning attachment means (133, 134) along long edges of pocket layer panels (131, 132) in a predetermined location spaced apart from the top and bottom of the long edge of pocket layer panels (131, 132) and joining attachment means (133, 134) to pocket layer panels (131, 132) by sticking seam, thus forming side pocket panels (136,137); forming expansion panel assembly by cutting panels (141, 142) to dimension, aligning attachment means (143, 144) to panels (141, 142) and joining attachment means (142, 144) to panels (141, 142) by stitching seam thus forming expansion panels (148, 149); forming expansion layer assembly by aligning and subsequently joining the side pocket panels (136, 137) to the expansion panels (148, 149) by seam thus forming side expansion panel sections (103,152, 153);joining the lower layer assembly and an expansion layer assembly by stitching an edge of the side pocket panels (136,137) to an edge of the side panel assembly on opposite sides of the mattress; the side panel assembly configured to place the expansion panel (103, 152, 153) along a side of the mattress; joining an upper sheet to the expansion layer assembly so as to attach the expansion layer assembly to both the lower sheet and upper sheet; and joining at least one attachment means to the edge of the side panel (109, 110) and the upper sheet so as to allow opening and closing the bed covering system; joining edges of side panels assembly and side pocket panels (136,137) by stitching a corner seam to form elongated pockets to tuck the side expansion panel sections (103,152,153); joining a gathering means to the free edges of the side panel assembly by stitching the gathering means to the free edges and of the side panels (109, 110) and the other free edges of panels (123, 124, 125, 126) to join these and form a perimeter.