Firmly established by long standing
encased in a hard shell.
Try the Bilibo, a hard shell of molded plastic that can be a hat, a bucket, a stool or a sit-and-spin.
If you routinely carry a lot of loose papers and files, it's best to buy a hard shell briefcase.
LeatherBriefcases.com offers a great selection of all types of leather briefcases of in both soft and hard shell.