What is the best glue to use in fastening cloth to plexiglass. Any help will be appreciated.

That is a tough one, as the glue can be seen from the other side if clear plexi. Does this matter?

I would try 777 spray adhesive or the sticky film sold in fabric stores. Peel and apply, then peal and apply the cloth. There are also several craft spray glues by 3M and Elmer's that should work.

Depending on the size, it will take 2 people to apply it without wrinkles.

I am thinking of covering a sheet of plexi if you are thinking of a box or other shape, it will be more difficult. It is not that glue will not stick to Plexi, most people want to glue Plexi together and still be clear, that is the reason for the assembly glue issues.

Thanks Bill for your input. The plexiglas will be opaque. I was thinking of maybe E6000 glue, but have not used that glue, only by what I have read about it. I will not be covering it to a box just fastening the cloth in places.

Devcon makes a 2 ton crystal clear epoxy designed for (among other things) plexiglass. You can find it at Ace Hardware. This glue has to be mixed in two parts and dries overnight. After application you can wipe the glue clean from the surface and the surface is beautiful. You can polish errant fingerprints away the next day as needed. Clamping is fine but not necessary. The 2 ton strength is incredible. The glue dries crystal clear and matches the acrylic index of refraction. It seeps into the micro cracks in the cut and completely seals the joint. The seal is totally waterproof, and the joints are beautiful.

Thanks Bill, I think that might be my answer. Thanks for your input in my project.

You could also try double stick carpet tape. It would not be permanent, but if the cloth needed replacing then carpet tape would have advantages over a permanent liquid adhesive.

There is a special adhesive specifically for plexiglass. It is administered through a syringe, almost dries instantly. You can purchase this at a plastics supply company, use this in a well ventilated area.