My youngest daughter came up with this cute little idea.  She wanted to play "kitchen" and needed a small milk carton to complement her little tea set.  She found a toilet paper roll and bent it into the shape of a carton and asked me to help her stick it in place.  I thought this idea was super cool so I took it a step further and gave it a cute Kawaii look with paint. I highly recommend using hot glue to hold the shape in place. If tape is all you have, go for it. But you may find that your carton will pop out of shape more easily with tape than with stronger hot glue.