Oh boy, I’m getting confused. I’ve been happily weaving PW on my new Spring2 and thought I understood the tie-up system, but….maybe not, now that I’ve come to the 3/1 & 1/3 twills. I’ve read Jane’s explanation in Foundation, but in my mind, the sample tie-up that shows PW, Lace, Warp and Weft has me 🤔. For a warp predominant fabric it shows that 1,2,3 are tied-up to the lower lamms and 4 to the upper lamm. If the lower lamms are the “risers” wouldn’t shafts 1,2,3 rise up out of the way allowing the remaining warp on 4 to be covered? Once the shed is changed and 1,2,3 come down again, aren’t those warp threads now predominant? Thanks to anyone who can set me straight!!

Yes, that was the article I was referring to. If I am raising 3 shafts, wouldn’t that create a warp faced fabric, since only 1 warp thread is covered by the weft?

Looking at the PDF on pg. 7 Twills on Four, there are numbers in the tie-up boxes; 1-2-3-4 for the 1:3 Warp predominant and 123-234-134-124 for the 3:1 Weft predominant twill. Am I turned around in thinking that I tie my lower (rising) lamms to these shafts? Should I be tying them to the upper (sinking) shafts instead?

Another resource to understand your 3/1 tie-up is to watch Season 3 Episode 4.5.....Tie Ups Variations including Twills, Boxes and Roman Keys at the Table. Jane explains it in that video.