Here are links to some of the common Composite Materials I use on my own plane & other Composite Projects

Each kind of Fiberglass, Carbon or Kevlar has typically has its own # for its designation, similar to how metals like 2024-T3 or 4130N are designated by numbers / letters. Lamination systems also have there own numbers / names. With Prepreg Materials typical nomenclature is “reinforcement / resin system” i.e. 7781/2510 for Toray 7781 fiberglass & 2510 prepreg resin.


For Fiberglass & Carbon’s I usually like AVT Composites:

Alternative source I use Thayercraft:

ACS usually has higher prices on fiberglass cloth styles & usually does not get the same packaging attention as AVT & Thayer shipments.


Dry-goods  Fiberglass & Carbon Data from



“The Rutan Cloths”



7725: is a 2X2 twill useful for going around compound curves (cowlings, fairings, wing tips etc…) wet out characteristics would rank as medium,

50″ wide:

38″ wide:




7715: is considered in the home built world as “Uni” most of its strength goes in the “1” or off the roll direction, useful for the 90º plies for Shear (if 0º is the long axis) can also be used for 0º longeron or spar cap plies in Major or minor structures. Cost / Weight / Effort wise for the Main Spar on the wing and stabilizer Carbon wins out for the bulk cap material, but 7715 still has its use in smaller less bulky layups.

38″ wide:




3733: from a Composite Design, Engineering & Fabrication perspective is my most favorite fiberglass cloth for general layups, outer skins, shear web, torsion ply materials, between the specs and testing this cloth is on the lean side of e glass Fiberglass products fro strength to weight, the fabric pattern depending if its twisted, flat or high density nesting flat can be a big player in strength to weight. 3733 is very easy to wet out & has excellent handling characteristics. its also a lower weight cloth than 7725 or 7781 making for less of a jump for your structural need = lower part weight. This also gives you better ply count resolution allowing you to carry less dead weight along in high ply count / taped ply applications.

50″ wide:




AGATE 7781/MGS418 wet layup data



7781: “The Infamous Aerospace Cloth” Chances are if you see a certified or military Fiberglass composite part good chances are its 7781. its a 8HS cloth configuration (under 7 over 1…) it has a good balance of flat and high contour performance. Fabric Resolution is in the 50’S/in (very high) allowing the material to act more uniform in smaller cross sections (edges with riveted nut plate / edge distance scenarios). Wet layup is painful, epoxy batches should be small and used quick for minimum Viscosity. Also highly recommend using a small short nap “pink” roller to process. speed is key, need fresh resin “in” cloth Quick!

50″ wide:


7781/2510 prepreg: manufactured by Toray Composites & being the major “yards sold / used in certified airframes” is the AGATE winner. Cirrus, Columbia & Liberty airframes are made out of the stuff. key reason for using it as the prime material on the NASA wind tunnel parts, its as turn key as you can get when it comes to Composites.



6781: is the slightly stronger S-Glass version of 7781, looks almost identical however due to the slight glass chemistry differences between e-glass & s-glass 6781 has a slight multi spectrum reflection visual effect. cost wise its in between 7781 & 282 / 284 carbon, however unless your boxed into a hard requirement for a “fiberglass material” the jump to the 2 carbons is not much. 6781 was used as P2 @ 45º for the shear web portion of my Flaps on my plane


Carbon Fiber:



282: plain weave, great basic use Carbon Cloth,



284: 2×2 twill



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