Trick to finding the edge of the base

You could also get a couple of pieces of 2 point hairline rule and lock them up against the sides of the base and print them on the tympan. Much less fussy work and easily repeatable when you have to change the tympan.

Bob

Another way of looking at it would be what I do. Place your pins where you know they’re out of the way. I just measure from the top of the bed to the bottom of the base and take the same measurement plus a little on the tympan. Tape your plate to your paper with something low-tack like painters tape and peel off the backer (if your plate is adhesive-backed). Put your paper and plate sandwich on they tympan. If necessary, make sure your press is on impression then close it fully. When you open the press, the plate and paper will be well affixed to the base in the right location. Peel the paper and tape off the plate and you’re done.
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Michael Hurley
Titivilus Press
Memphis! TN

What about using glue dots instead of painters tape? It is available is various tack strengths placing in non image area to allow for squeeze?
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Ted Lavin
Artificer Press

I expect it would work fine. I just happen to have painters tape around.
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Michael Hurley
Titivilus Press
Memphis, TN

Personally, I stick a folded papertowel under the tympan, make the impression, pull the towel out, and mark over the crease with a pencil.

Quick & dirty.

foldedtowel.png

How slack is your tympan when you pull the towel out, and how much of the take-up from correcting that slack moves the position indicating crease?

Well, I’m drastically exaggerating the bump for dramatic effect there. The error margine is about 1mm, which I can live with. If there’s any noticable sag, opening the bale and quick tightening takes but a moment.

I like the folded towel idea - I will have to give it a go. Sounds quick and easy.