Brief description

Movable type refers to individual pieces (usually metal) that carry a single alphanumeric character or punctuation mark in relief on one face. These pieces can be assembled to form words, lines, and pages of text, and then disassembled and reused infinitely to compose new texts.

Use / Function

Its primary function is to allow flexible and reusable text composition for printing:

• Text Composition: Allows forming any combination of words and sentences without having to carve an entire page every time.
• Reusability: Once a page is printed, the types can be “distributed” (returned to their cases) and used for the next one.
• Correction: It is easy to correct typos by simply changing the affected characters before printing.
• Scale: Fundamental for the mass production of books and documents.

Operating principle

The system relies on standardization and modularity:

1. Uniformity: All types must have exactly the same height (“height to paper”) so the press applies uniform pressure.
2. Body: The size of the metal block (body) determines spacing and alignment.
3. Alloy: The use of a specific alloy (type metal) allows casting fine details that harden quickly and withstand press pressure without deforming immediately.

How to create it

The process of creating movable type (type founding) requires great precision:

1. Punch Cutting: A craftsman carves the letter in relief on the end of a hard steel bar. This is the most difficult and artistic step.
2. Matrix Making: The steel punch is struck against a softer copper bar, leaving a deep impression of the letter (the matrix).
3. Matrix Fitting: The matrix is filed and adjusted to ensure it fits perfectly into the mold.
4. Casting:
   • The matrix is placed in an adjustable hand mold.
   • Molten alloy (lead, tin, antimony) is poured into the mold.
   • A quick motion is made to ensure the metal fills every corner of the matrix.
   • The mold is opened, and the type is ejected.
5. Finishing: Excess metal (the “jet”) is broken off, and the base is sanded to have the exact required height.

Materials needed

• Type Metal: Alloy of Lead (main volume), Antimony (hardness and expansion), and Tin (fluidity and toughness).
• Punch: Hardened steel.
• Matrix: Copper.
• Hand Mold: Steel, brass, and wood.
• Cases: Wood to organize the types (upper case for capitals, lower case for small letters).

Variants and improvements

• Wood Type: Used for very large letters (posters) where metal would be too heavy and expensive.
• Linotype: Machine that casts entire lines of text at once (19th century), greatly speeding up composition.
• Monotype: Machine that casts and composes individual characters automatically.
• Digital Typography: The modern evolution where “types” are software files.

Limits and risks

• Wear: Metal types wear out with repeated use and pressure, losing sharpness.
• Toxicity: Constant contact with lead poses a serious health risk (lead poisoning) for typographers.
• Complexity: Creating a full set of punches and matrices for a font requires years of expert work.
• Weight: Composed forms of type are very heavy and difficult to transport without disordering them.