Weaving has a lot of jargon, so for readers who are unfamiliar with these terms I'll define shed, so you don't think I'm talking about a building to store things in. :) The Shed is created by raising some shafts/threads and not raising (or in some cases lowering) others. I weave primarily on countermarche looms, so for the rest of this entry I will refer to raising and lowering shafts. The shed occurs when some threads are up and some lowered, this is the place you put the weft yarn and is the crux of weaving, without a shed you can not truly weave, the debate over the accuracy of this statement is left to those who wish to engage in said debate.The perfect shed is a wonderful thing, but can require a lengthy journey to achieve. The perfect shed (right) is one where all the lifted warps align with each other and all the lowered warps are even with each other and plenty of room is created for the shuttle. As stated earlier, you can weave with sheds in which one set of threads is higher or lower than others, but this is not ideal.You can make due with less than perfect shed, but the perfect shed takes enjoyable weaving to the point of sheer euphoria! There are many reasons weavers should take the time to achieve the perfect shed. The number one reason is not the extra pleasure you get from weaving with the perfect shed. The perfect shed, , makes weaving more efficient and consistent. When all the threads align and there is plenty of room, the chances of mis placing the weft are very small. The perfect shed takes away any doubt as to whether the weft thread is going over and under the right threads. When I am confident in my weaving I weave with much less tension in myself and my warp, this leads to much more ideal results.This is why I encourage all weavers to take the time when you first buy a loom, or set up a loom for a new structure, to look at the shed and make the necessary adjustments to achieve perfect sheds. Yes it takes some time to go through each sequence in the treadling and figure out why are the threads in shaft 1 higher than those in shed 2, should I raise shed 2 to the level of 1 or lower shed 1 to the level of 2. I can tell you that taking the time to evaluate each treadle (or treadling sequence on a table loom) is well worth it. You will enjoy your time weaving more, your end product will be far less likely to contain errors, and it's just good practice.Yes it is more problematic to have uneven threads in the base of your shed, but I do find having the threads in the top and bottom of the shed makes a difference in my enjoyment and accuracy in weaving. Ultimately the choice is up to the individual, but I would ask all weavers to check their sheds, if you have one that is uneven just once take the time to adjust it and see if it makes a difference to you. If it does great! If not, that's fine too.Happy Weaving!!!