Thermal Binding Covers: Sizes, Colors, and Materials Explained

Cover specs get confusing fast, spine size, color, and material are three separate decisions, and product listings don't always make clear which is which. This is a plain reference for all three.

Sizes

Spine size refers to the width of the spine, which determines how many sheets a cover can hold, not the cover's overall page dimensions (that's determined separately by letter, legal, or A4 format). Peleman covers span a wide range, from just a few sheets up to 340 sheets in the highest-capacity spine size, with sizes in between covering everything from a short memo to a substantial bound manual. Our spine size guide has the full sizing chart matched to page count, worth checking before ordering since sizing wrong is the single most common cause of a disappointing bind.

Colors

Cover color options vary by cover type. Flex Covers, for example, come in Black, White, Dark Blue, Quartz, Aluminum, Bordo, and Dark Green spine colors, giving a reasonable range for matching brand identity or simply keeping document types visually distinct in a shared office. Soft and Hard Covers typically offer their own separate color and finish ranges, and Custom Covers remove the constraint entirely since they're fully printed to your own specification.

If brand consistency matters, matching a specific color across a run of documents is worth confirming at order time, since color availability can vary by cover type and spine size.

Materials

Spine Covers provide only the steel spine, no front or back panel material, since you supply your own.

Flex Covers are a lightweight plastic construction, a clear front panel and a frosted back, with no rigid board. This keeps them light and consistent for high-volume, repeatable use.

Soft Covers use a flexible but more substantial material than Flex Covers, durable enough for regular handling while remaining lightweight.

Hard Covers use rigid board, cased-in construction for a genuine hardcover book feel, the most durable option for anything meant to be kept long-term.

Custom Covers vary in base material depending on the finish ordered but are always fully printed to specification, material and branding decided together rather than separately.

How These Three Specs Interact

Size, color, and material are independent choices, a Hard Cover comes in a specific spine size and a specific color or finish, and changing one doesn't require changing the others. The practical order to decide in: figure out your spine size first (based on page count), then choose the material that matches how the document will be used, then pick a color or finish that fits your branding.

Browse the full range of covers across all sizes and materials, or start with the spine size guide if you haven't sized your document yet.