One of the quality features of a plane is a stable base which will not twist or warp with age or use and which is accurately ground for flatness and squareness to the sides
In addition, finely machined seating’s are required in order to eliminate movement and juddering (sometimes described as chatter) of the blade and a strong simple mechanism (usually lever cap) for a firm hold on the cutter assembly in use, but with easy release for re-sharpening and replacement
The quality of the cutting iron is an essential feature, allowing it to be finely sharpened and honed and to hold a long-lasting cutting edge
The plane should have simple positive fine adjustment
