3Di 760, 780 & 870
North 3Di technology stretches the boundaries of sail performance

3Di™ is a unique, patented sailmaking technology that allows laminated sails to approach the balanced loadbearing and shapeholding of a rigid airfoil. In simplified technical terms, 3Di is a flexible composite membrane built from spread filament tapes pre-impregnated with glue, arranged in multiple axes to form a membrane and then thermo-formed on a 3-dimensional (3DL) mold.

With 3Di technology, designers have such precise control over the placement and orientation of material within the sail, they can come far closer to achieving balanced resistance to distortion in all directions. Less distortion = more drive.

Product Highlights
  • Unique, patented technology using an array of spread filament tapes to form a composite membrane with no film
  • Balanced resistance to distortion in all directions makes 3Di approach the performance of a rigid foil
  • Available in Carbon/Dyneema* or Aramid/Dyneema* composite styles

* Ultra-high molecular weight polyethylene, produced under the trademark Dyneema® or Spectra®.

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Learn More About 3Di
3Di Q&A

A spread filament tape is an individual yarn thathas been spread out until the individual filaments lie side-by-side,forming an ultra-thin "tape." Shown here is a pre-preg carbon/Dyneema* spread filament tape a mere 35 microns thick.
3Di Features - Mainsails and Headsails
  • 3DL thermo-molded construction
  • Aramid/Dyneema composite foil (760), Carbon/Aramid/Dyneema composite foil (780) or Carbon/Dyneema composite foil (870)
  • Loose-footed main with Integral Foot Skirt for shape and control
  • Luff customized to mast/boom or headstay system (except for custom luff cars)
  • Stainless steel round rings (Titanium if loads indicate a better fit) and Rutgerson press rings
  • RBS epoxy “E-glass” battens
  • Pockets with 3Di tie in closure
  • Cunningham adjustment
  • Pre-stretched Technora or Vectran leechline and footline
  • Telltales
  • Drawstring sailbag
  • Higher roach profiles through added area
  • Custom 3Di layouts and tape styles
  • Custom reinforcements
  • Reefs
  • Water reefs
  • Reef keepers and flaking handles
  • Full length battens
  • Flutter battens
  • Leech battens
  • RBS Carbon leech battens
  • RBS Carbon full length battens
  • Overhead leech cord
  • Sail numbers
  • Country code
  • Insignia
  • Trim stripes/Glow Fast stripes
  • Photo and corner codes
  • Certified measurement
  • Custom, roll or zippered sausage bag
  • Telltale window
  • Leech, Full or VB+ vertical battens in any quantity or combination
  • RBS Carbon leech battens
  • Inflatable batten pockets
  • Customized patches, pads and reinforcements
  • Spreader and stanchion patches
  • Soft hanks
  • Soft clew
  • North Clewboard
  • T-ring clew
  • Adjustable head loop
  • Tack Snap Shackle
  • Sail numbers
  • Country code
  • Trim stripes/Glow Fast stripes
  • Photo and corner codes
  • Certified measurement
  • Roller reefing layout and patches
  • Rope Luff Reefing Pad and patches
  • Reef
  • UV protection
  • Custom, roll or zippered sausage bag
3Di 760
composite foil

3Di 780
composite foil

3Di 870
composite foil