How small is the hanger? Could it hang in a closet on the clothes rod?
yes it can hang on a standard size clothes rod
What material is on the inside? Plastic or canvas or soft fabric?
The whole thing is made of canvas and PVC and has plastic pockets with double zippers on both sides. It holds a lot of stuff and does it really well.
Would this hang on the back of a door?
Yes. That’s exactly what I did. It’s hung on the back of my closet door. Works perfect.
Can it be used for travel?
Yes, this one has a zipper, so your jewelry can be well protected. If you think it is too big, you can buy a small size, which is suitable for travel