dot wheeln. now rare a toothed wheel mounted in a handle, which when rolled over a surface produces a dotted line, by scoring, inking, impressing, etc., the surface.
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1884 St. Nicholas May 572/1 You may finish by going over the outline with a dot-wheel.
1961 Technol. & Culture2 47 Early duplicates were made by..tracing over (like carbon paper) with scriber or dot wheel.