Instruction: Given a question and the related document, and generate the answer to the question based on the information provided in the document.

Input:
Question: Will this unit "Smoothly" roll up a 9'W x 20'Lg heavy muslin cloth?  & What about total Weight, & Clearance between other Muslim rolls?
Document: There seems to be some sagging already since the rolls do not roll up smoothly. The end support wobbles when you pull the roll up. The kit did not come with the proper hardware for mounting the brackets to studs in the wall. I highly recommend mounting to studs, since it can be very heavy once the paper is hung. The price was cheaper than most, so all in all we are happy with the purchase.
Since the muslins do not come on cardboard rolls, I will buy 10' long PVC, aluminum or cardboard pipes/rolls and use them with the muslin. Home Depot has cheap PVC 10' pipes for $3.50 each. I'll tape the muslin to the pipe and use it the same way I do the paper.If you need to conserve space and want ease and speed, this is a great unit at a great price.
I recently installed this unit to the ceiling joists in my studio (works on walls or ceiling). It holds up 3 rolls of 9 foot wide seamless paper. I love it. First, it takes only seconds to lower one background and raise another. Second, not big heavy rolls to lug around. Third, it saves floor space (no awkward stands required) and is much more stable than floor stands, which can tip and crash to the floor if you aren't careful, especially if working alone.
it dented my paper before I could stop it ,in other words you have to very carefully let the back drop down, this I can live with. But trying to roll up a same size canvas/muslin is a disaster ,it rolls up so uneven it looks totally cheesy, not professional at all.
If your backgrounds are already on a roll (as paper, vinyl, etc. often are), then you do not need PVC to put them on a roll. The PVC is needed for when you are putting up muslin or canvas that don't come on rolls. You can use the wall mount system directly into the paper roll!
I purchased this to hang seamless paper in my home studio. Not being very handy with tools, I paid a home contractor I found on craigslist $100 to mount 2 sets of these on my ceiling (to hold a total of 6 rolls). A couple of observations:1. The metal brackets aren't super super strong. They hold fine under normal use, but can get bent when mounting a roll of seamless if you smack the bracket hard enough with the roll of paper.2.
I only use 5' wide seamless paper and the chains easily do the job. I suppose if you were to use heavier backdrops such as heavy cloth, then you might want to upgrade to the metal chains. Also, I mounted these to the ceiling, not to the side of a wall, and it works well.
One other thing i recommend adding is some weight to the edge of the paper/muslin, so that it comes down strait, and stores in a higher position.
Until it sets up it will just keep oozing out. So ...duct tape or finger for about ten minutes. I tried the finger method, you don't want to use that. My muslin back drops have been hanging for about two weeks, deployed the rolled back up several times and the PVC shows no signs of bowing. Just be gentle with the plastic chains with the weight of the muslin. Buy them , they're worth the price.
I screwed mine into the wooden ceiling with drywall screws, rather than into the wall with the included hardware. The brackets work either way, on a wall or ceiling.To prepare the paper and muslin backgrounds for installation, I put a weight at the bottom of each background so that it would stay tight, taught and reduce problems with wrinkles and so on when being used, and also to keep it from spinning loose when not being used, especially with the paper.
Answer: I don't use it with muslin but I can say it does hold the weight, I have a roll of white vinyl up there that is pretty heavy and just like another comment, it does "get away from you". It will unroll all the way once it is started. I have a plastic ring that I hook through one of the links and to jam it at the top, have to use a ladder. The PVC pipe worked really well to hold it, just hit it with the staple gun then smoothed it with some wide tape.