Substrate Glossary

Plain-language definitions of the terms used across our substrate pages and datasheets.

APET

Amorphous PET, unmodified clear thermoplastic polyester. Common in packaging.

C of C (Certificate of Conformance)

Document certifying material meets specified properties; issued per shipment.

Calendered film

Film produced by passing molten resin through heated rollers; common for rigid PVC.

Cast film

Film produced by extruding molten resin onto a chilled roll; produces high optical clarity.

Corona treatment

Surface treatment that increases ink and adhesive adhesion on polyolefin films.

Cut-to-size

Sheet trimmed to custom dimensions per customer spec.

Draw ratio

Ratio of finished part depth to opening width in thermoforming.

Extrusion

Process of forcing molten resin through a die to produce film, sheet, or profile.

Foam PVC

Expanded rigid vinyl with closed-cell structure; lightweight, machinable.

Gauge

Material thickness, typically expressed in mils (thousandths of an inch) or millimeters.

HIPS

High-Impact Polystyrene; styrene with rubber modifier for impact resistance.

HDPE

High-Density Polyethylene.

LDPE

Low-Density Polyethylene.

Mil

One-thousandth of an inch (0.001"). Standard gauge unit for film and thin sheet.

Mylar

Trade name (DuPont) for biaxially-oriented polyester film. Often used generically.

PETG

Glycol-modified PET; clearer and more formable than APET.

Print-grade

Substrate qualified for a specific print process (toner, indigo, inkjet, etc.) with appropriate surface treatment.

RPET

Recycled-content PET.

Sheeting

Converting roll material into discrete sheets at a specified length.

Slitting

Cutting roll material to a narrower width.

Specific gravity

Material density relative to water; affects yield and freight cost.

Substrate

The base material onto which printing, lamination, or fabrication is performed.

Synthetic paper

Plastic-based sheet that prints, folds, and finishes like paper but resists water and tearing.