The immovable object spell description says, in part (Explorer's Guide to Wildemount, p. 187):
You touch an object that weighs no more than 10 pounds and cause it to become magically fixed in place. You and the creatures you designate when you cast this spell can move the object normally. [...]
If the object is fixed in the air, it can hold up to 4,000 pounds of weight. [...]
Does the immovable object spell prevent damage to the target?
For instance, say a PC throws a blanket around themselves to make a "cocoon" around them and then casts immovable object on the blanket. Would enemies be able to damage that object (e.g. cutting through it with a weapon or setting it on fire)?
My reason for asking is this: If you rip up a fabric, it's inherently being moved. And if it can support 4000 pounds, it seems like it must have some level of invulnerability.