If one is brave a determined one could steek each side of a sweater, meaning cut it, and then sew it together at a smaller size and cut off the excess. You would have to sew on a machine a line or two of stitches on each side you want to cut to prevent raveling and then mattress stitch the new edges together. But it would depend on the sweater and pattern as to how easy this would be. Easier with a plain sweater than say a lacy or cable one where the design might be disrupted. It would be more difficult with slippery yarn as well. The sleeves might need dealing with in a similar manner also.
One can also rip out the bottom to make it shorter and re-knit the lower edge.
All this is scary but possible I think.
May Peace Prevail on Earth.
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