the present invention provides a frame having variable dimensions , comprising a plurality of telescoping legs arranged in first and second pairs , with each leg of said first pair being rotatably coupled together and each leg of said second pair being rotatably coupled together ; and a scissor link mechanism coupled between the legs of said first and second pairs to vary a length of said plurality of legs in response to a distance between said first and second pairs varying . in one embodiment one end of each of said legs of said first pair is rotatably coupled together and one end of each of said legs of said second pair are rotatably coupled together . in this manner , the dimensions of the frame may be varied to accommodate support of a flexible body , such as a plastic bag , paper sack , fabric sack and the like to provide the same with a desired volume and / or an opening of the same with desired dimensions . specifically , the length of the legs , the angle therebetween and the distance between the first and second pairs may be such as to provide a desired volume of structure support to the flexible membrane from amongst range of volumes that the flexible material can support .