From time to time I get emails from new weavers wondering what is going 'wrong' with their projects. There are so many ways for things to be 'wrong' and sometimes it is a matter of scale
Many people use warp packing that is simply too weak for a longer warp. While light weight paper or Venetian blinds work just fine for shorter warps, longer warps may exert too much force and the packing material simply cannot withstand the pressures. When this happens the warp can start to spread, the beam becomes cigar shaped, the outside ends no longer roll on the same length/circumference as the middle of the warp and bad things can start to happen.
If you find yourself in this position there are two ways to deal with it. If the difference in length of the outside ends and the middle ends isn't terribly great and you are weaving short items (tea towels, place mats) you can go ahead and begin weaving to see if the difference is going to make that much of an impact on the cloth. A yarn with a certain amount of elasticity will cope with a slight difference in circumference and when it starts to impact the cloth you can just cut off, straighten the ends and re-tie. This is much faster than the second option but may cause issues if you are trying to weave longer items (scarves, yardage).
If that is the case the only real option is to roll the warp forward and re-beam using a more sturdy type of warp packing. Many people use sticks. Unfortunately wood has become increasingly expensive and inserting individual sticks into a long warp takes time. They often don't unload very well and you have to get up and go to the back of the loom to remove them or the weight of them building between the warp and the beam as they come out of the layers of warp can cause issues with advancing the warp.
Long time readers of this blog will know that my preferred warp packing is bamboo blinds with the hardware removed. I leave the header on but remove all the metal bits and string for raising and lowering them. The blind goes into the warp intact and simply rolls on as the warp goes round the beam. The added benefit is that instead of inserting a dozen sticks I only add one blind and roll on. Quite often they are also self-unloading as well.
I have 5 blinds which generally is sufficient for the up to 11 meter long warps I routinely beam. Some of them are getting quite old in terms of number of times of use and I'm thinking I may need to replace some of them. Generally buying one blind is cheaper than buying the number of sticks to put into a warp although sticks never need to be replaced. But most people don't weave nearly as much as I do and therefore are unlikely to need to ever replace the blinds like I'm think I may need to do one of these days.
And last, a picture of some of the scarves cut off the loom since I got home. Not a vanity shot because they still need their fringes twisted and to be wet finished.