Instruction: Output yes if the supporting document can answer the given question. Otherwise, output no.

Input:
Question: is it too slippery to use it on grass?
Document: I bought the blue and yellow and know it will get some use on the grass at navy football games as well ;)
really like it, the only draw back is that it is not machine washable. we got it to use with our son when outdoors and it is big enough that we can contain him to the blanket without having to constantly pull grass out of his hands prior to eating.
A couple shakes was all it took to remove any sand, and only an additional 15-20 seconds was needed to stuff the sheet back into its attached storage pocket. Because the ParaSheet is very thin, I would use a traditional picnic/beach blanket for the added thickness when sitting on grass or rough turf.
The Parasheet is easy to take out and put back into an attached stuff sack. It's a very light and compact item that fits nicely in my family bag that we use. We used it today for an impromptu picnic on a patch of grass. Worked out fine. We will be using this often on the  grassy outdoor poolside areas and at the beach. It's much larger than the picture. When unfurled, it can easily seat a group of six adults.
Took this to on a vacation to Hawaii to use on the beach and it packs up very small. It's very light and the sand shakes right off (as long as it is not damp or wet sand). The sheet is very thin but that is what I expected. I would not recommend using it on grass as the blades will probably poke through. Machine washable and easy to store. I would buy another one and recommend this to someone who is looking for a small, portable beach blanket.
I bought the Parasheet after reading the favorable reviews about it and I absolutely love it! We use it on the grass and on the beach and it works wonderfully. It's NOT waterproof but it makes an excellent beach or park blanket when conditions are dry. It doesn't pick up the sand or dirt, it packs easily in its own attached pocket and it's lightweight and dries quickly. It's big enough for 3 adults and it has corner pockets and stake loops to anchor it to the ground.
So it's great at the park in the grass. Less comfortable on harder ground if that's a concern.
i guess i should of read it (parasheet) because I didn't realize it was going to be the material of a parachute. But it works great. Had it on the beach and grass. would recommend it!
Its easy to get back in the bag.Nothing sticks to it.Cool to touch in the grass on a hot day even in full sun.
The size is great and I love how it can be folded into a bag. It is lightweight and easy to tote around. Unfortunately, it is not at all waterproof. We laid it on wet grass and were soaked.
Answer: yes