The obvious insert to use for the WeeCare shell is the WeeCare Onesize, which easily goes into the cover with a popper at each end.
The Onesize insert fits in both sizes of Easy Covers and consists of materials that are naturally absorbent. The Onesize insert consists of four layers of absorbent hemp fabric (a blend of 55% hemp and 45% organic cotton, topped with the softest bamboo velor (55% bamboo viscose, 25% organic cotton and 20% polyester), which rests against baby's skin.It has a hint of stay-dry effect, which means that it does not feel nearly as wet such as pure cotton.
The bottom layer of the onesize insert has waterproof PUL fabric that protects the cover so it doesn't get wet easily, so the cover can be used again if it has not become particularly wet or dirty.
The onesize insert is open in the middle to allow air to flow through as it hangs to dry, drying faster than if all layers of fabric were sewn all the way around the edge.
The inserts have leakage barriers in the sides, which consist of soft microfleece fabric, which helps with containment, and also helps to protect the cover from getting wet or dirty.