Where to buy tempen/mylar

I’m thinking Mylar and tympan are two different things, no?

Tympan can refer to the topsheet or drawsheet, “the tympan”, or it can refer to tympan paper in general. Mylar can be the drawsheet, and so you can call it tympan in that case, but if you use it as a hanger sheet, it wouldn’t be tympan.
NA Graphics sells precut Mylar drawsheets for Vandercooks. I use Duralar, bought in rolls at an art supply store.

Mylar is a clear protective top sheet. It’s what they make those novelty Happy Birthday balloons out of. You don’t have to use mylar but it helps keep your tympan clean. It’s very thin (.007”) You can buy mylar at your local art store and cut it down.

Tympan is an oiled paper used for the topsheet in your packing. Below the tympan go the undersheets. All of these things can be purchased at nagraph. http://order.nagraph.com/vandercook-tympan.html

And of course, make sure the height of all your packing matches the correct height for your cylinder’s undercut (usually .04”).

There’s already a great thread on here about vandercook packing: http://www.briarpress.org/17962

Mylar comes in a variety of thicknesses.
I’ve bought rolls online, from these guys: http://www.eplastics.com/Plastic/Clear_Polyester_Film

Preston

Thinking you really mean, tympan [oiled] manilla/manila.
Tympan being the hard, tense and oiled character of the material, not unlike the tympan on an orchestral drum. The actual stock is the manilla/manila.
Its usefulness in letterpress printing is to provide a top sheet underwhich makeready sheets and makeready was done. Its durabuility and cost were accessible in those days. The technology may have been superseded.
William Amer, Rockley NSW