Paper converting has its own working vocabulary, and it shows up fast on a first call with a converter: parent roll, core ID, OD, basis weight, tolerance. None of these terms is complicated on its own, but mixing two of them up — or guessing at one you have not heard before — is a common way an RFQ goes back and forth longer than it needs to.
This glossary defines the terms that come up most often when buying converted paper, in plain English and in the order they matter to a buyer. It intentionally keeps each definition short: for the fuller picture of what converting is, see our guide to what paper converting is, and for a deeper walkthrough of a roll’s physical parts, see our guide to the anatomy of a paper roll.
How to Use This Glossary
Terms are grouped into five categories, roughly in the order they come up when preparing a quote: core process terms, roll and dimension terms, material and quantity terms, quality and handling terms, and buying and order terms. Use the table of contents to jump straight to a term, or skim top to bottom — this is meant to be a quick reference, not a full encyclopedia, so each entry is a sentence or two rather than a deep dive.
Core Converting Terms
- Paper converting — transforming paper from the large, mill-scale rolls a paper mill produces into the sizes and roll formats a manufacturer’s equipment can actually run.
- Converter — a company that performs paper converting; also used informally for the machine doing the work.
- Contract converting / toll converting — a converter processing material the customer already owns, rather than material the converter sources itself. See custom paper converting for how this fits into a full order.
- Slitting — cutting a wide roll into one or more narrower rolls. See paper slitting.
- Rewinding — transferring paper onto a new roll, changing the core size, outside diameter, or length without changing the width. See paper rewinding.
- Slitter rewinder — the machine that unwinds, slits, and rewinds a parent roll into finished rolls in a single pass. See how a slitter rewinder works.
Not sure whether your job needs slitting, rewinding, or both? See our guide to what each process actually changes.
Roll and Dimension Terms
For how to take these measurements accurately, see our guide to measuring a paper roll.
- Parent roll — the large, mill-scale roll a converter starts with; also called a jumbo or master roll.
- Finished roll — the converter’s output: paper slit to a specified width and wound to a specified core, diameter, or length.
- Web — the paper itself, considered as one continuous ribbon as it moves through converting equipment.
- Core — the rigid tube, usually fiberboard, that the paper is wound onto.
- Core ID / inside diameter — the opening inside the core that fits over an unwind shaft or chucks; this is the number that must match your equipment.
- Outside diameter / OD — the roll’s total diameter, core and paper included, measured across the end face.
- Roll width / web width — the dimension along the core, from one edge of the paper to the other; the dimension slitting changes.
- Face — the roll’s curved outer surface, spanning edge to edge.
- Edge — where the web ends at either side of the roll; on a converted roll, a cut surface made by slitting blades.
- Wrap — one complete layer of paper around the roll.
- Wind direction — which surface of the paper faces out and which way the web unwinds; matters when the two sides of the material differ.
Material and Quantity Terms
- Basis weight — the weight, in pounds, of a set count of sheets cut to a grade’s standard size; how paper grades are named and compared.
- Caliper — the thickness of a single sheet of the material.
- GSM — grams per square meter, the metric basis-weight scale; unlike basis weight, GSM compares directly across different paper families.
- Linear footage — the length of the web on a roll; usually calculated from the OD, core size, and caliper rather than measured directly.
- Roll weight — the weight of a roll; stated as net (paper only) or gross (including core, packaging, and pallet).
Quality and Handling Terms
- Tolerance — the allowable variation from a specified dimension before a roll is considered out of specification.
- Width tolerance — allowable variation in slit width; Paper Dimensions holds every slit order to ±1/32″.
- Length tolerance — allowable variation in a finished roll’s footage; Paper Dimensions holds rewound rolls to ±1%.
- OD tolerance — allowable variation in a finished roll’s outside diameter; Paper Dimensions holds rewound rolls to ±1/2″.
- Telescoping — a roll’s layers sliding sideways into a cone shape, usually from a winding-tension problem.
- Crushed core — a core deformed into an oval or collapsed, usually from clamping force or impact; a crushed core will not mount on a shaft or accept chucks.
- Edge damage — nicks, dents, or tears along a roll’s edges from handling.
Buying and Order Terms
- Customer-owned inventory — material held by the converter and released against the customer’s production schedule, rather than shipped all at once.
- Blind shipment — an order shipped under the customer’s own branding, with no indication of who converted it.
- Customer-arranged freight — the customer arranges all inbound and outbound freight; Paper Dimensions packages and stages finished rolls for pickup or the customer’s carrier rather than providing shipping itself.
- RFQ / request for quote — a description of the material and roll specifications sent to a converter for pricing. Our guide to preparing an RFQ walks through exactly what to include, or you can request a quote directly.
Key Takeaways
- A converting quote is built from two rolls: the parent roll you have, described by width, OD, and core ID, and the finished roll you need, described the same way.
- Width, OD, and core ID are three independent numbers — a roll can be right on one and wrong on the others, so all three need to be stated.
- Tolerance terms (width, length, OD) describe how much variation is acceptable, not the target dimension itself.
- Terms like customer-owned inventory, blind shipment, and customer-arranged freight describe how an order is handled, not how the roll is made — worth stating up front if they apply to your job.