A plastic insert is configured to provide support of thin wafers in wafer carriers configured to provide peripheral wafer support. The invention includes the insert, the insert in combination with a wafer carrier, and the methods of supporting the thin wafers as provided by the insert and the wafer carrier. The inserts, in preferred embodiments, utilize tabs that fit into the side wall recesses and have an interference fit in said recesses to secure the insert in place. In preferred embodiments the inserts have a top surface with a plurality of ribs positioned inwardly from the wafer periphery for supporting the wafers with minimal contact. In preferred embodiments the insert has a lower surface having strengthening structure providing rigidity to the insert. The top surface ribs may preferably be oriented parallel to the insertion and withdrawal direction of the wafers and extend upwardly to position the supported wafer in the slot immediately above the slot defined by the recesses in which the tabs are positioned. Thus, the inserts may be inserted into alternate slots in the carrier. The insert, in preferred embodiments may have an h-shape offering an optimal combination of support of each wafer and precise positioning of the wafer while minimizing the amount of plastic and correspondingly the weight of the insert.