Wire side and Felt side

Also referred as wire side and top side. The side which is in contact with the paper machine wire during paper manufacture is called the wire side. The other side is top side. Certain properties differ between wire and felt side and it is customary to measure these properties on both the sides. In case of paper to be printed on one side only, best results are obtained by printing on felt side. Postage stamps are printed on wire side and then gummed on felt side, where the smoothness is helpful for attaining an even application.