Cross-Cut Laminate – Racing Mainsail

A Beneteau 40.7 with yellow aramid Flex main and genoa.

Sails made with cross cut panels are the most economical sails to make because there is very little cloth waste. Sails made with Flex laminates are designed to be the least expensive laminate sail since they can be made with cross-cut panels without having to be reinforced with load-bearing tapes.

To understand the unique structure of Flex, one needs some background on sail construction. A cross-cut sail has all panels parallel to each other and perpendicular to the straight-line leech. This construction utilizes sail cloth that has the stronger yarns going across the panel instead of along the length of the roll of cloth, see inset in Diagram 1. In woven cloth, the yarns running across the roll of cloth are called the “Fill Yarns” and the yarns running along the roll are called “Warp Yarns.” A cloth that has stronger yarns in the fill direction is called a “Fill Oriented” cloth.

Diagram 1. Cross-cut panels with Fill Oriented cloth shown oriented perpendicular to the straight-line leech. The inset shows the “fill” and “warp” thread directions. In a fill oriented cloth, the fill yarns are stronger than the warp yarns.

FLEX is a fill oriented cloth made of a loose weave of warp and fill yarns that is bulked up with yarns in four more directions around the fill yarns. See Photo 1 below.

The purpose of two sets of X-Ply yarns, more in-line with the fill yarns, (highlighted in blue and yellow) is to pick up the loads going up and down the leech. In a “string sail” e.g. Tape-Drive, X-Drive and Titanium, the continuous yarns or tapes smoothly carry the loads between the head and the clew along the leech. In a tri-radial sail, the long, narrow panels are angled so that long, strong warp yarns can be aligned with the leech loads. In FLEX sails the two sets of X-Yarns are there to pick up the loads not perfectly picked up in the cross cut layout.

Flex cloth for racing sails uses aramid yarns or polyester yarns. 


Photo 1. Fill yarns shown in blue, warp yarns shown in red, 20° X-Ply yarns shown in green and 30° X-Ply yarn show in yellow. The two sets of X-Ply yarns are closer to the fill direction than the warp direction to support the loads along the leech, where the highest loads in the sail run.

The extra X-Ply yarns can be seen well when you click on the picture to enlarge it.

A Beneteau 40.7 with an aramid Flex mainsail and No. 3 genoa.


Available Details

Available with:
– Reefs
– Loose Foot
– Cunningham
– Telltales
– Draft Stripes
– Sail Numbers
– Leechline


Available with:
– Double Taffeta
– Single Taffeta
– Partial Taffeta


– Powerhead
– Full Battens
– Square Top


Other options:
– Sail Cover


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