Press sizes are determined by measuring the inside dimension of the chase. Thus, a 10x15 C&P, also called a "platen" press, has an actual chase measurement of 10x15, and the "platen" measures 11 1/8 x 18 1/18. Please use the chase dimension only when ordering tympan for your "platen" press.
Treated Tympan is made in diecut sizes for all standard Vandercook, C&P, Kluge, and Heidelberg presses, both Platens and Cylinders. It is made with the highest degree of uniformity, and without either hard or soft spots and is .006" thick. Mylar top sheets (or tympan) serve to give sharp, clear impressions and is part of the typical "hard" packing method. It requires the use of good type or plates, and in all type forms, where old and new type, or wood type, is used, then a softer top sheet in the rubber type will work better. When ordering Mylar, specify what Vandercook press it is for and we cut it to size using original Vandercook templates. One price per sheet for any size Mylar, cut to a specific Vandercook press or as a rectangle. Maximum size on this single pricing is 25" x 41".
What to use? Hard packing and hard tympan is usually preferred for most letterpress applications. Soft packing leads to type and plate wear, will not give sharp impressions, and will leave an embossed impression in the tympan and packing of whatever was being printed. Deep impression is also best achieved when the paper fibers are compressed rather than punched through the back of the sheet and the use of soft packing to achieve this is usually a mistake. The packing paper we sell is accurately made for the specific purpose of press packing, and is available in several thicknesses, and provides the essential foundation for proper printing. Don't do more than your press is capable of doing, and most table top presses are not suited for deep impression work. The key is to experiment and see what works best.
Tympan paper made in the United States is currently manufactured by the Sunshine Paper Company in Denver, Colorado. Sunshine purchased the Cromwell Paper Co. of Chicago in 1986 and acquired the Riegal line of tympan from the James River Paper Co. when that company shut down some years back. The current tympan and packing papers made by Sunshine are a mix of the Cromwell and Riegal specifications. Some of the Sunshine paper line is sold exclusively by certain distributors, like Day International. Why is Sunshine in Denver, certainly not a major graphic arts center like Chicago? The owners preferred living in Colorado--the same reason we're not in Cincinnati where NA Graphics started.
Roll tympan and certain sizes of the press packing are special order. Rolls take from one to three weeks for Sunshine to ship, and press packing is about one week. Our cut sizes of press pack (TP488 and TP488a) are stock items here at NA Graphics.
Polycarbonate tympans work well with Takach scraper bars as they have a very smooth surface, resulting in less friction. Polycarbonate tympans will possibly scratch and should be handled with care. Larger polycarbonate tympans will become increasingly difficult to handle and stabilize. When raised for inking, large polycarbonate tympans may flex and fall onto the work surface. The flexibility allows the printer to curve the polycarbonate tympan as it is lowered to meet the paper and matrix, reducing the contact surface area. This will create less air pressure between the paper and tympan resulting in less registration shift.
G-10 tympans resist scratching, and are rigid. This makes them easy to stand up against the pressure assembly of the litho press. As G-10 tympans wear the fibrous core is exposed, this greatly increases the friction, and the tympan should be replaced. The cost of shipping G-10 tympans may be prohibitive, as they are extremely rigid and ship in large packages as a result.
A frame covered with parchment, on which the sheet of paper to be printed is placed. This is the outer tympan; the inner tympan fits into it, and between the parchments of the two the blankets are placed, all which being run in receive the pressure of the platen, which produces the impression on the paper.
Each notebook contains 10 blank white sheets (40 pages) and a used tympan for the cover. Because the tympan is oiled, wax paper is used as the endsheets and frosted mylar is used for the outer cover to protect both the inside pages and everything outside the notebook. The frosted mylar covers are letterpress printed with handset type. Each tympan is completely unique and was carefully selected and cut to be aesthetically pleasing. Notebooks measure 3" x 5" and are saddle-stitched with 2 staples.
Useful configuration for hard, yet resilient, packing:
Treated or oiled sheet such as Drum Head/Lithpak II to protect metal cylinder (or similar). Additional Drum Head/Lithpak II (or similar) and Riegal to pack. At least one additional cut-to-form-size Riegal as stretched taped on tympan to prevent burnishing of printed sheet. To prevent matrixing, change out undersheets on a per job basis. Replace PolyPak tympan top sheet if impression marked.
(Severe marking may also damage Kimlon bottom sheet). Kimlon serves to even out impression on older presses. And is invaluable in that regard (treat it kindly).
38c6e68cf9