When I needed to carry art materials around without a car (packs of paper, glass, board and framed paintings etc), I designed this "CARRIER" for the purpose. I needed something for sizes that one could not carry under one's arm.
By adjusting the strings of the "CARRIER" to its maximum length or by pulling it shorter with knots at each side, one can carry a variety of sizes. It works best when there is not too much space between the armpit and the top edge of the object to be carried. A heavier item also provides more stability and the shoulder carries the weight well while hands are free for carrying a shopping bag or opening doors etc.
Quite large sizes of object can even be carried while cycling as long as there is room to steer and pedal. Ultimately one can walk with the packet resting on the pedals of the bike.