A ruler is a rigid measuring instrument used in the picture framing, drafting, and art industries for accurately measuring distances and for drawing straight lines. Unlike flexible measuring tools such as tape measures, a ruler provides a stable and straight edge, making it particularly valuable for precise layout work, mat cutting, and determining artwork dimensions.

Function & Purpose

Measuring: Provides accurate linear measurement, typically in inches, centimeters, or millimeters.
Drafting: Serves as a straightedge for creating consistent, straight guidelines in matting and frame design.
Quality Control: Used in the framing shop to verify artwork size, mat openings, and frame dimensions against specifications.
Calibration: Ensures accuracy when aligning cutting tools, squaring moulding, or marking mounting boards.

Types of Rulers

Wooden Rulers: Traditional and affordable, but may warp over time.
Metal Rulers: Durable and precise, often preferred in professional framing and mat cutting.
Plastic Rulers: Lightweight and transparent versions allow easy visibility of underlying artwork.
Specialty Rulers: Variations such as cork-backed rulers (to prevent slipping) and T-squares (for right-angle accuracy) are common in art and framing work.

Advantages

Provides precise, repeatable measurements.
Can double as a cutting guide when working with knives or blades.
Rigid structure ensures accuracy over flexible measuring tools.
Portable and simple to use in both workshops and studios.

Limitations

Limited length (typically 12-48 inches) compared to tape measures.
Rigid form makes it less practical for measuring around curves or large objects.
Wooden rulers can warp or wear, reducing accuracy.

Best Practices

Use a metal ruler with a cork backing for precise cutting and measuring in frame shops.
Pair with a tape measure for larger measurements and dimensional confirmation.
Keep ruler edges clean and undamaged to preserve accuracy.
Store flat to prevent warping or bending.

Ruler