equipment in use at the Excelsior Press

Printing Digital Art & Illustrations on your press

You can make up your printing form and print from hand-set Foundry Type, Linotype, Ludlow slugs and various stock-cast cuts & dingbats. But if you want to print original artwork, you will need to either have a wood or linolum block cut by an artist or use either an engraving or a photo-polymer plate.
Any relief plate that is type high (.918") can be used on the platen or proof press.

The most popular options are the engraving or "cut" and the "photo-polymer plate"
Read on to learn more about these options

PHOTO-ENGRAVINGS - MAGNESIUM & COPPER
PHOTO-POLYMER PLATES

Traditional Metal Photo-Engravings for letterpress

Photo engravings are relief plates, typically acid-etched deep enough to print with on a letter press and mounted on wood blocks, cut to the size of the image.

Engravings can be produced from black on white line art delivered to the engraver or from digital image files submitted via email. These engravings are typically mounted on wood blocks cut to the size of the image and can be locked up in the chase along with hand set .918" high metal or wood type, Linotype, Ludlow slugs or other engravings.

Note: Old, used engravings typically sell on eBay for $5-$20 each plus $3-$5 shipping

These plates are typically etched in magnesium and mounted on wood, although a variety of materials, mounts and plate thicknesses is available for a variety of letterpress purposes. Many engravers offer more than the standard 16-gauge engraving, but for simply printing an image, the acid-etched, wood mounted Magnesium Photo-Engraving is what we use most often.

Typical Costs (using Owosso Graphic Arts published pricing for example July, 2010)
The cost of an engraving is based upon its size in square inches. The chart below is a very basic example of costs we can expect.

plate type
8 square inches
30 square inches
per square inch
16 gauge Magnesium on wood
$14
$31
.44
Copper 
$21
$32
1.60
1/4" Magnesium on magnesium base
$44
$130
3.30
Female Embossing die
$30
$50
1.60

Female embossing dies - which allow the printer to do traditional embossing which raises the image from the front of the sheet by squeezing the sheet between the female die in the chase and a matching male "counter" mounted or cast of resin or other materials directly on the platen, are also available. Embossing produces a truly classic relief image on the paper, works well on paper as light as text or bond and has been around for ever.

Recently, the simpler alternative, called "debossing" has come into fashion, but it is nothing more than printing hard on soft, thick, compressible paper without ink. Embossing and debossing require quite a bit more impression than simple printing.

One popular supplier of all sorts of engravings is Owosso Graphic Arts of Owosso, Michigan. When our local engraver closed his doors in the late 1970's, we began ordering our engravings by mail from OGA and have been pleased with the service and quality. When newspapers were printed letterpress, engravers served all major cities in the US. Many engravers still serve printers across the U.S., but they are not nearly as common as they once were.

A full price list for photo engravings - in .pdf format - is available from Owosso Graphic Arts at their web site - Download OGA Pricelist Note that our guide above is very basic. Other charges may apply. Inform yourself before ordering.

Visit Owosso Graphic Arts to learn more about their products and services. A phone call to speak with a rep about your needs is recommended when you place your first order.

Photo-Polymer Plates were introduced to the general job printer in the 1980s and are all the rage these days and do print just as well as the traditional metal engravings - but printing with photo-polymer is just a little bit different than with metal.

The main difference in printing with photo-polymer plates has to do with roller height and pressure. Photopolymer plates prefer a lighter inking, which means setting your rollers a bit higher than you might want to use for printing with type or traditional engravings. Photopolymer plates are thin and, while they can be mounted on wooden bases cut to the size of the plate, they are typically mounted on a reusable and somewhat expensive "base", which is commonly larger than the image - typically almost as large as the press' chase.

Photo-polymer plate makers typically accept digital art via email.

When BASF first offered photo-polymer plate material to the small-town printer during the early 1980's, we made our own photopolymer plates - just as we made our own offset plates. We mounted ours on old wooden engraving bases.  You can make your own if you'd like. Unlike etched metal plates, no acid is required, just a negative, an exposure unit and a water-wash-off tray or sink. But you can also buy top-quality plates at reasonable prices from a number of plate makers.

One leader in this field is Boxcar Press of Syracuse, NY.

Typical Photo-polymer plate costs:
Note: many plate types are available, but for platen presses, the deep-relief plate is recommended
plate type
8 square inches
30 square inches
per square inch
Deep-Relief KF152 adhesive plate
$30
$30
.67
$30 minimum, $.54-$.67/square inch
These plates are easily cut with a trimmer or Exacto knife, so it makes sense to fit many images onto one order and cut them apart for individual printing, by simply removing one plate from the base and mounting another onto the same reusable base.

A 10x15" plate = 150*.60=$100.50

Plate Mounting Options
Boxcar Press recommends mounting their plates on their very popular aluminum "Boxcar Base", which are priced from $150-$1150 and can be locked up into the chase. Since it must be locked into your existing chase, it is smaller than the chase size to allow for the use of furniture and quoins to lock it into place.

To maximize image capability for smaller platen presses, Excelsior Press has developed a full-size "Chase-Base" which completely replaces the normal frame chase with a single large blocked Cherry Wood "Chase-Base", precision-milled to a set height and cut and precisely fitted to replace the chase of your press. No quoins or furniture are required with the Excelsior Chase-Base. Prices for the Chase-Base range from $68 for a Kelsey 3x5 to $98 for the 8x12 Chandler & Price, with a dozen of the most popular platen presses of various sizes currently supported.

Included with every Excelsior Chase-Base are flexible, un-smashable gauge pins which let you position your sheet anywhere on your platen. Extension Feed Guides, which allow placement of the lower gauges as low as 1" below the lower edge of the platen are also available - and highly recommended for presses 5x8 & larger.


Visit BoxCarPress.com to learn about their Boxcar Base and the plates they make.
Vist the Excelsior Press Museum Fund-Raising Page for more information on the Excelsior Chase-Base
Note: While both processes can create halftones for printing photographs, letterpress really shines with line art. Although photographs have been printed on platen presses for well over 100 years, photographs are a special case these days and offer interesting challenges to the letterpress printer - particularly the new letterpress printer.

We recommend that you stick to line art - drawings - at least in the beginning, just to make printing with your platen press a bit less frustrating.

And, for that deep-impression that is so popular these days, the deeper engravings (thicker plate) may do a better job for your - BUT use only IF your press can handle the pressure without breaking. Be careful when you "punch" your paper...

page last updated July 25, 2010
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