I did not think that this paper could be of much interest here because it deals with the problems in LP reproduction, not the production itself, but 340 views of the post about the tracing paper (https://www.lathetrolls.com/viewtopic.php?f=1&t=10062) in less than two days made me think I might have been wrong.
Unlike the tracing paper, which was mainly a historical survey with little original material, this one has a complete analytical solution for the optimum overhang and offset angle for the so-called “Löfgren C” alignment (Least Mean Squares distortion over the disk, rather than the Tchebyshev or mini-max optimization criterion, aka “Lofgren A” and “Bearwald” alignment).
The problem has been unsolved since 1938, when it was initially formulated by Löfgren [3], but it is mainly of theoretical interest. The most important practical result is that tracking error null radiuses (where the protractors for “Löfgren C” force the zero error) should be at 70.0 and 116.0 mm rather than at 70.3 and 116.6 mm as the previously used approximate formulas suggested, but that difference is probably too small to be audible in any practical circumstances.
The complete paper is available for free (without a subscription to AES) at https://www.aes.org/e-lib/browse.cfm?elib=21560. Their Open Access policy allows free downloads but does not allow posting the paper on other sites.
