I have tried several times to post a rather long story about how and why, but Weavo doesn't like it... that long story can be found on my blog.

Let's see if I can get some pictures up...

They are both woven on the same warp (linen 16/1, sett at 12 ends/cm), and the same threading.

The tie-ups are different, and the wefts - the top one has linen 16/1 for weft, the bottom has cotton 16/2.