One nice thing about running a linecaster, or in this case my Intertype, is that you have a boundless supply of type to print with, limited only by your ability to spell and typemetal on hand. With that however, is the need for the mats to be in reasonably civil shape. Old mats get beat up on the sides and eventually this gets into the casting cavity, causing metal to go where it oughtn't and creating what are called (and look like) hairlines.
Now there are a lot of reasons why hairlines appear, but it usually is a terminal condition that can only be cured (at present) by finding a font of mats in better shape and treating them very nice. The best way to treat hairlines is to not let them get started in a font, and that requires taking care of spacebands and making sure that the vise on the first elevator is in tip top shape. Also, and this might pain you, but if you see a dented or dud spaceband in the box---out it goes--don't wait a minute.
What gets frustrating is that all of these things are made of unobtainium. Now, I think it is possible to make new spacebands--and there are plenty out there still in good shape, but nobody has quite figured out how to cut new matrices--yet. Hoping they hurry up, or it may well wind up as one of my future projects.
I'll put a scan of the job that brought this essay about, but my scanner can't do the hairlines justice. Now whether others might just say that such artifacts are quaint (just like beat up wood type is considered rustic) has yet to be seen, though it would be handy. (click on image to see enlargement and pick out hair lines in "Show and Swap Meet"
For those curious, SEPTEMBER is 14pt Vogue Med Condensed, the 19 is 6 line (1 inch) wood type, the rest of the form is 14pt Futura Medium with "Show and Swap Meet" in 18pt Vogue Medium. The paper is actually a die-cut window from another project (1000's of 'em, waste not!). Overall size is 1 3/4" x 4" Will have to talk about those die-cuts later.