Read the Fibre Direction: A Guide to Lint-Free Cutting of Cardboard, Paperboard and Corrugated

The edge quality of cardboard, paperboard and corrugated board often depends on how you manage the fibre direction before the knife. Correct alignment reduces "feathering", limits tearing and reduces waste. The following practical framework can be quickly implemented in everyday workshops and packaging work.

1) Quickly "read" the fibre orientation

• Cardboard: It is usually sufficient to gently bend one edge in two directions. The direction that bends easily is often considered to be the MD (Machine Direction); the relatively resistant side is considered to be the CD (Cross Direction - the direction perpendicular to the MD). In a simple tear test, the tear is flatter along the MD and more "hairy" on the CD.
• Corrugated cardboard: The direction of the flutes is an important clue. When cutting parallel to the corrugations, the blade runs more smoothly; when cutting perpendicularly, fibre breaks and tears may be more pronounced.

Ergonomics Tip: Aligning critical cutting lines parallel to the MD as much as possible when placing parts reduces both labour and blade consumption.

2) "Scoring → deepening" approach
Especially when cutting in the CD direction, going deeper in one step can increase edge distortion. First, the cutting line is stabilised with a very light pass (scoring) and then the cut is gradually deepened and completed in 1-2 steps.

• In cardboard and paperboard, this method ensures a clean cut without breaking the fibres.
• In corrugated cardboard, especially when working perpendicular to the flutes, scoring reduces breakage on the outer surface.

3) Ruler and angle adjustment: Line management

• Metal ruler + non-slip base stabilises the line.
• When the blade comes to the surface at about 10-20°, the cutting edge "cuts" the fibres; at higher angles, the pubescence is reduced.
• For long lines, fixing the ruler to the body side helps to limit deviations.

Note: A flat, non-stretch cutting mat improves edge integrity, especially in corrugated board, by preventing voids from forming under the flutes.

4) Short strategy guide for material

• Cardboard (single layer): Lines parallel to the MD give smoother results. For CD cuts, first use light scoring and a low angle.
• Cardboard (multi-ply): There is a tendency for delamination at layer transitions. Multiple light passes and pressure with a metal ruler control layer "slippage".
• Corrugated cardboard:
• Parallel to corrugations: Light pressure and a long, flowing motion provide a clean edge.
• Perpendicular to the grooves: Scoring + gradual deepening + low angle reduces surface "pop".
• Coated surface detail: Starting the cut on the side with the pressure and/or coating significantly reduces tearing and coating lifting at the point where the blade emerges on the opposite side.

5) Blade, blade and mechanism selection

• Snap-off blade: When the blade is blunt, the segment is broken off to produce a fresh blade immediately, making it efficient for fine work at 9 mm and long lines at 18 mm.
• Blade geometry: 30° tip in detail; TiN-coated segments stay sharp longer for a long series of cardboard-corrugated cuts.
• Locking preference: Screw clamping bodies increase blade stability on long and deep lines; automatic locking adds speed on flowing jobs.
• Parcel cutting & thick corrugations: Trapezoidal/hook inserts cut tape and thick corrugations in a controlled manner; PRUK06 (with automatic retraction) supports safe and fast work on these jobs.

Product matches from UTTIL:

• Precision lines (cardboard): PTUK07-30 (9 mm, 30° tip)
• Long lines/stability and deep cutting: VMUK coded series (screw lock, 18 mm)
• Serial groove cuts: PTUK08-EX (18 mm, TiN-coated grizzly horse)
• Fluent general use: NMUK09 (18 mm, ergonomic HIPS+TPE housing)
• Parcel cutting / dense packaging: PRUK06 (trapezoidal/hook bit, automatic retraction)

6) Planning habits that reduce waste

• Layout: Position the parts so that the critical lines are aligned with the MD.
• Marking: Marking MD/CD with a small arrow on the back of the cutting material can speed up repetitive work.
• Sample cutting: Testing the angle-print-pass combination on a small piece of a new type of board/cardboard eliminates most errors in the first place.

7) Without compromising safety
Routing the line away from the body, carrying the blade closed/locked outside of work, and replacing blunted blades in a timely manner increase confidence as well as control.

Conclusion
What makes the difference in edge quality is not only the right blade, but also the correct management of the MD / transverse CD direction. "Locking" the line with scoring, gradual deepening at a low angle and clever positioning of the ruler result in cleaner edges and less waste.