King StarBoard® XL is a lightweight, marine-grade, cellular high-density polyethylene sheet that is up to 30% lighter than the original King StarBoard®. It is the product of a proprietary process called K-Stran™, the most advanced manufacturing process for superior flatness and consistency. King StarBoard® XL has a matte finish on both sides of the sheet. It is environmentally stabilized to withstand the harshest outdoor conditions. King StarBoard® XL will not rust, delaminate or rot when exposed to UV, humidity or water. It is ideal for a variety of marine applications from boat components to equipment mounts, and looks good enough to use in high-visibility applications where structural strength and a finished edge are not important. For maximum versatility, standard colors are made to coordinate with the original King StarBoard®. The polymer sheet never needs painting or refinishing, works like wood, and is easy to fabricate with common woodworking tools and techniques.

King StarBoard XL is upgradable to King MicroShield® with an advanced antimicrobial technology for protecting the product surface against stain and odor causing bacteria, algae and fungi.*

For more information about King MicroShield®, please visit product page.

Disclaimer: King MicroShield® may affect color.

Where to Buy

*For bacteriostatic, fungistatic, & algistatic properties. This product is exempt from registration under 40 CFR 152.25(a). King MicroShield® effectiveness verified by ISO and ASTM standards. This product does not protect users or others from disease-causing bacteria. Always clean this product thoroughly after use.


Standard Sheet Size

in: 60″ x 96″
mm: 1524″ x 2438″

Standard Gauges

in: 1/4″ 3/8″ 1/2″ 3/4″
mm: 6.4mm 9.53mm 12.7mm 19mm

Approximate Weight

lbs: 40 lbs 61.5 lbs 80 lbs 120 lbs
kg: 18.14kg 27.89kg 36.28kg 54.43kg

Tolerance information:
Gauges 1/4″ up to 3/4” ± 5% | Length and width plus only at room temperature

Custom sheet sizes, gauges and colors available

Physical Properties
Properties Units ASTM Nominal Values
Density g/cc D792 0.77
Tensile Strength @ Yield psi D638 >3,300
Tensile Modulus psi D638 165,000
Elongation @ Yield % D638 9.6
Flexural Modulus psi D790 130,000
Flexural Stress @ 5% Strain psi D790 2,990
Compressive Properties 10% Strain psi D695 2,910
Durometer Shore D D2240 64.9
Izod Impact Resistance ft.lbs./in.2  D256 1.4
Heat Deflection Temp. 66 psi ºC (ºF)  D648  87ºC (188ºF)
Screw Holding Strength lbs D1761 325

All values are determined on specimens prepared according to ASTM.
Nominal values should not be interpreted as specifications.
King StarBoard® XL is made entirely from FDA and USDA approved material.


Additional Information
  • Unique (closed-cell) cellular marine-grade sheet.
  • Weighs up to 30% less with the same surface finish as King StarBoard®.
  • Ideal for fabricating any boat part where high structural strength or a finished edge is not required.
  • Precise tolerances ensure consistent color, thickness and density–even for thicker gauges.
  • Holds staples and screws securely.
  • Environmentally stabilized for harsh sun and tough marine environments.
  • Will not rot, swell, splinter or delaminate when exposed to humidity or water.
  • Resists odor, even in wet environments.
  • Easy to clean and never needs refinishing.
  • Matte-textured finish on both sides.
  • Easy to fabricate using standard woodworking tools.
  • Available in eight standard King StarBoard® colors to match or accent any gelcoat.
  • Unlimited custom/proprietary colors.
  • Forms easily for smooth curves.
  • Available in large sheets up to 60” x 96”
  • Custom sheet sizes available.
  • Shipped with a protective masking on one side.
  • Proven on thousands of boats and yachts.
  • Experienced boat builders and boaters know the King StarBoard® brand and trust it more than any other.