The invention is particularly directed to the problem of creep deformation in a coiled aluminum strip, which occurs during coiling and for a period thereafter. The problem arises because the profile of the strip across its width is not flat, and is in fact usually thicker in the middle than at the edges (positive crown). To compensate for this, the invention provides that the spool onto which the coil is wound is adapted to provide more support to the strip in the center than at the edges, by making the central portion of the spool of a greater diameter than the end portions of the spool. A strip having a positive crown which is wound onto such a spool was found to exhibit significantly reduced creep strain, leading to reduced creep deformation.