Presto

From 2-faced lines: centers Scoot Back and Press Ahead to become #1 and #2 of columns. Ends do a Tandem Cross Fold to become #3 and #4.

\sxvlines{b1e,g1e,g2w,b2w} \syhlines{b2e,b3e,g3e,g2e}
1 3 1 3 2 4 2 4 2 4 3 1 3 1 2 4
before Presto after


If done from waves, a collision occurs, resulting in "clumps".