Microwave splatter covers are available for purchase from Amazon, Walmart and Bed Bath & Beyond. The range of different covers varies based on the retailer, with Amazon having the largest selection, as of 2015.
Amazon features the Ikea Microwave Lid, Kitchen + Home Silicone Suction Lids, ZestPod Microwave Cover and Cooking Splatter Guards, Norpro 2067 Microwave Cover, Miles Kimball Vented Microwave Cover, Pratico Kitchen EZ-Lid Silicone Lids and Food Covers, ATB Plastic Microwave Plate Lid Cover with Steam Vent and WalterDrake Deluxe Microwave with Vent. Many of these covers come in a set of different sizes. For example, the BellaLore Silicone Lids come in a set of four sizes: 6, 8, 10 and 12 inches. These particular lids work best with smooth surface dishes, and they are also usable in the oven, refrigerator, freezer and dishwasher.
Walmart sells the transparent Nordic Ware Microwave Spatter Cover, which fits the size of the average dinner plate. The plastic cover has a vented lid, and it requires hand washing to clean.
Bed Bath & Beyond sells numerous microwave splatter covers, including the MiracleWare 2-Piece Microwave Food Cover Set, Progressive Microwave Food Cover and Oink Oink Microwave Lid. It also has the Tovolo Microwave Collapsible Food Cover, which is useful for compact storage and traveling.