This one is an experiment in using my Shannock loom with four heddle bars set up as a 1-2-3-4 threading. This would be the same thing as threading a straight draw on a four shaft floor loom.
With this arrangement a "double sett" can be woven in which plain weave (alternately one up, one down in the warp) may be used, and also what's usually called a basket weave in the fabric weaving world (alternately two warps side by side are up or down). Woven in this weft faced way the basket weave is essentially an enlarged plain weave.
To weave plain weave with every-other warp either up or down, the heddle bars threaded on 1 and 3 would alternate with those on 2 and 4. For the other "basket weave" arrangement of paired warps the heddle bars 1 & 2 are used alternately with 3 & 4. In this on my loom, both 8 ends per inch and 4 ends per inch may be woven by my choosing to use either 1-3, 2-4 or 1-2, 3-4. Of course, one could do this selection by hand. Threading for this arrangement just sort of speeds up the picking of the sett (speed being a relative concept in tapestry weaving).
Here's the loom with the heddle bars arranged in a stacked way to have the warps threaded through 1, 2, 3, 4:
With the 4 epi sett I'm using six strands for the weft bundle--two of 20/2 worsted wool and four of Vevgarn. For the 8 epi sett there are three strands, one of 20/2 worsted and two f Vevarn.