Types of Letterpress Printers Blocks
Posted on February 18, 2009 by admin
Line Blocks are made from copper or zinc and are approximately 6 points thick. They are mounted on hardwood, usually boxwood, to make a finished height of approximately .918 inches (type-high)
Halftone Blocks are made from zinc or copper and are approximately 6 points thick. The image is broken up into small dots. They are mounted on hardwood, usually boxwood, to make a finished height of approximately .918 inches (type-high)
Electrotypes have a copper printing surface backed with stereo metal and are approximately 12 points thick. They are mounted on hardwood, usually boxwood, to make a finished height of approximately .918 inches (type-high)
Stereotypes are made from plastic, rubber or an alloy of lead antimony and tin and are approximately 12 points thick. They are mounted on hardwood, usually boxwood, to make a finished height of approximately .918 inches (type-high)
Note: Stereotypes and electrotypes can be nickel faced for longer life. To identify each, compare the non-printing areas. The stereos usually are rough in these areas and electros are usually quite smooth.
Wood type are solid blocks of hardwood with raised image on the topside.
Linoleum Blocks are a this sheet of linoleum mounted to a hardwood block. The linoleum is manually carved to created the preferred graphic.
Types of Block Faces
Zinc: all zinc plates are originals, since they are produced by an acid-tech process from a photographic negative. They are usually glued to the wood base, which is either plywood or solid, occurs about half and half. Sometimes nails are used, but this is not normal. Metal is light in color, not as dark a grey as older cuts, and they are light in weight. There are almost always small overlapping circles following the image area, made by the router used to remove excess background material. Metal is consistent in color and tone throughout its depth, rather like aluminum.
Modern-day cuts are often magnesium, which is even brighter and lighter, glued only, no nails. Zinc is usually corroded at some place; white, powdery residue. Corrodes VERY easily. Zinc cuts may or may not have a color on their surface, most commonly blue, green, amber, or red, depending on the amount of use they received. The color is simply that manufacturer's choice and does not apparently relate to the quality of the cut. It's there to help increase the life of the material.
Stereo: made from a mold, no machine marks on the surface. Consistent dark grey throughout material thickness, image area has a "sculpted" look to it, as if carved from butter and shaped by modeling tools. Most always mounted to a solid block, usually hardwood: oak, maple, etc. by nails. In the middle third of 1900's was sometimes glued to the block. Heavier than zinc or magnesium, solid "feel" or heft. Thick is older than thin, the heavier, the older. Supposedly, the first experiments in stereotype happened in 1683, but it did not become common until the mid-19th century.
Electro: identical in manufacture and physical characteristics to the stereo, except that the surface has been electroplated with copper to increase useable life. Examining the edge of the cut through a 10-power loupe, the copper plating is easily seen. As before, thicker is older. Consistent color, usually dark grey, throughout material depth. Also as before, darker is older. Virtually always mounted with nails to solid wood base. Some electros were designed for very heavy use and are made of solid type metal with an electroplated copper surface. Common for newspaper production work, where the type and cuts really took a beating daily, especially in the 19th century.
Copper plate: generally not used in letterpress work, but more for music engraving and art prints. They are not mounted to a base, as a general rule, and are most often used in a copperplate press. Thin material, engraved on one side only, copper throughout, generally not an alloy. A real treasure if you find one. Used from beginnings of printing right up 'til today. Easily damaged.
Type Size Terminology
Foundry type is measured in “points”, wood type is measured in lines or picas. Graphic blocks can be measured by either.
1 inch = 6 pica = 6 lines
1 pica = 12 points
72 points = 1 inch
Standard Type Height = .918 inches
Halftone Blocks are made from zinc or copper and are approximately 6 points thick. The image is broken up into small dots. They are mounted on hardwood, usually boxwood, to make a finished height of approximately .918 inches (type-high)
Electrotypes have a copper printing surface backed with stereo metal and are approximately 12 points thick. They are mounted on hardwood, usually boxwood, to make a finished height of approximately .918 inches (type-high)
Stereotypes are made from plastic, rubber or an alloy of lead antimony and tin and are approximately 12 points thick. They are mounted on hardwood, usually boxwood, to make a finished height of approximately .918 inches (type-high)
Note: Stereotypes and electrotypes can be nickel faced for longer life. To identify each, compare the non-printing areas. The stereos usually are rough in these areas and electros are usually quite smooth.
Wood type are solid blocks of hardwood with raised image on the topside.
Linoleum Blocks are a this sheet of linoleum mounted to a hardwood block. The linoleum is manually carved to created the preferred graphic.
Types of Block Faces
Zinc: all zinc plates are originals, since they are produced by an acid-tech process from a photographic negative. They are usually glued to the wood base, which is either plywood or solid, occurs about half and half. Sometimes nails are used, but this is not normal. Metal is light in color, not as dark a grey as older cuts, and they are light in weight. There are almost always small overlapping circles following the image area, made by the router used to remove excess background material. Metal is consistent in color and tone throughout its depth, rather like aluminum.
Modern-day cuts are often magnesium, which is even brighter and lighter, glued only, no nails. Zinc is usually corroded at some place; white, powdery residue. Corrodes VERY easily. Zinc cuts may or may not have a color on their surface, most commonly blue, green, amber, or red, depending on the amount of use they received. The color is simply that manufacturer's choice and does not apparently relate to the quality of the cut. It's there to help increase the life of the material.
Stereo: made from a mold, no machine marks on the surface. Consistent dark grey throughout material thickness, image area has a "sculpted" look to it, as if carved from butter and shaped by modeling tools. Most always mounted to a solid block, usually hardwood: oak, maple, etc. by nails. In the middle third of 1900's was sometimes glued to the block. Heavier than zinc or magnesium, solid "feel" or heft. Thick is older than thin, the heavier, the older. Supposedly, the first experiments in stereotype happened in 1683, but it did not become common until the mid-19th century.
Electro: identical in manufacture and physical characteristics to the stereo, except that the surface has been electroplated with copper to increase useable life. Examining the edge of the cut through a 10-power loupe, the copper plating is easily seen. As before, thicker is older. Consistent color, usually dark grey, throughout material depth. Also as before, darker is older. Virtually always mounted with nails to solid wood base. Some electros were designed for very heavy use and are made of solid type metal with an electroplated copper surface. Common for newspaper production work, where the type and cuts really took a beating daily, especially in the 19th century.
Copper plate: generally not used in letterpress work, but more for music engraving and art prints. They are not mounted to a base, as a general rule, and are most often used in a copperplate press. Thin material, engraved on one side only, copper throughout, generally not an alloy. A real treasure if you find one. Used from beginnings of printing right up 'til today. Easily damaged.
Type Size Terminology
Foundry type is measured in “points”, wood type is measured in lines or picas. Graphic blocks can be measured by either.
1 inch = 6 pica = 6 lines
1 pica = 12 points
72 points = 1 inch
Standard Type Height = .918 inches
