the printed line produced on the <#web> by the <#rotpress=rotary press> at the point where two <#plate=plates> met. Two plates were used in combination with each other on the classic <#rotpress=rotary press>. Each plate would fit over half of the printing <#cylinder>. Ink would gather in the joints between the plates, leaving an impression (a joint line) on the <#web>. One complete revolution of the press cylinder created two joint lines on the web. Joint lines were produced on both <#sheet> and <#coil=coil stamps>, but only those produced on the coil stamps are commonly collected. A Joint Line is not the same as a <#guideline=Guide Line>.