# 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://r2r.tech/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](https://r2r.tech) 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] or [scu6x] controller interface.

**Category:** Technical

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## About Roll-2-Roll Technologies

Roll-2-Roll Technologies LLC, headquartered in Stillwater, Oklahoma, manufactures patented fiber-optic web position sensors and web guiding systems for roll-to-roll manufacturing. Products include ODC edge sensors (48mm to 960mm), 1DC all-in-one sensors, SCU-series controllers, and complete web guide systems.

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