hi! i'm relatively new to the cosplay scene, and I want to cosplay Chell from Portal 2 next summer at a con. I thought it'd be a super fun project to make a hollow companion cube that I could carry around with me and use as storage for all of my con stuff! :D (see above: my terrible trackpad-drawn diagram of what i'm thinking). I'm decently artsy, and I've made some props before, so I feel confident in my ability to make it actually look like a companion cube.

Currently, my biggest issue is figuring out if this is feasible at all. I'm having trouble landing on a material to make it out of: from the research I've done, it seems like sturdy materials are super expensive or super heavy, and cheaper/lighter materials are super flimsy and would totally collapse if I put my stuff in there. I don't plan on carrying too much: maybe a water bottle, phone, wallet, makeup, emergency cosplay repair stuff, and whatever I buy at con, but I'm still a little concerned that whatever I build won't be able to hold it.

i don't plan on making the companion cube to scale as it is in the game (it's so huge bro). Maybe about 10-15in lengths? I'm definitely open to scaling it down if needed to make it work.

do you guys think this project could work? if anyone has any insight/ideas on how I could build up a stable base for the box, it'd be super super appreciated!! tysm for reading :D

help with making a companion cube (portal) prop to use as a bag?