Just follow the rules for submission at the NGCcoin.com website. Use 2 1/2 x 21/2 non pvc flips for smaller items and 4 x 4 (or larger) non pvc flips for larger items. Many original hard capsules permit the coin or medal to move around, causing rub spots/wear. If the design projects beyond the height of the rim, this permits the high point to rub on the hard capsule (and this is a problem). Still, if the design does not project beyond the height of the rim and if the coin or medal does not move around in the hard capsule, send it to ngc or ncs in the hard capsule. Without doubt, pad the items well to avoid movement within the box and use double boxes to avoid impact damage during shipment. Registered USPS mail is the safe way to ship (although it is very slow).
Mark Bonke