# When should I use line guiding instead of edge guiding on an unwind application?

> The choice between edge guiding and line guiding depends on what defines "correct position" for your process: Use Edge Guiding When: The physical web edge is your reference (e.g., die-cutting to edge, edge-aligned lamination) Material has consistent, clean edges Processing unprinted or solid-colo...

**Last updated:** 2026-02-01

**Source:** https://live-roll2roll.pantheonsite.io/resources/faq/when-should-i-use-line-guiding-instead-edge-guiding-unwind-application

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## Question

When should I use line guiding instead of edge guiding on an unwind application?

## Short Answer

Use line guiding when processing pre-printed materials where the print position matters more than the physical edge, or when edge quality is inconsistent but printed registration marks are reliable.

## Detailed Answer

The choice between edge guiding and line guiding depends on what defines "correct position" for your process:

**Use Edge Guiding When:**

- The physical web edge is your reference (e.g., die-cutting to edge, edge-aligned lamination)
- Material has consistent, clean edges
- Processing unprinted or solid-color materials

**Use Line Guiding When:**

- Processing pre-printed materials where print registration matters more than edge position
- Web edges are inconsistent (ragged, variable width) but printed marks are reliable
- Guiding to a coating edge rather than the substrate edge
- Running materials with printed registration marks or tracking lines

**The Roll-2-Roll Technologies Advantage:** With [ODC 960](https://r2r.tech/products/sensors/odc-960) wide-aperture sensors, you can switch between edge and line guiding modes without changing hardware. This is particularly valuable for slitter rewinder applications that process both plain substrates (edge guide) and pre-printed materials (line guide) on the same machine.

The sensor automatically adapts to detect either the physical edge or a contrast line based on your selection in the [SCU5](https://r2r.tech/products/sensor-controller/scu5) or [SCU6x](https://r2r.tech/products/sensor-controller/scu6x) controller interface.

**Category:** Technical

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## About Roll-2-Roll Technologies

Roll-2-Roll Technologies designs and manufactures patented fiber-optic web position sensors and advanced web guiding controllers — the precision measurement and control core of modern roll-to-roll manufacturing. Spun out of Oklahoma State University's Web Handling Research Center and trusted by Fortune 500 medical, battery, and nonwovens manufacturers, our patented sensors work without recalibration at ±0.1mm accuracy up to 760 mpm — typical customer outcomes are 50%+ less downtime and payback under six months. Headquartered in Stillwater, Oklahoma, our team of PhDs, controls engineers, and industry veterans extends the sensor + controller core into complete web guide systems including stepper-motor-based linear actuators (RLA, BLA, LHS).

- Website: https://r2r.tech
- Phone: +1 (888) 290-3215
- Email: sales@r2r.tech