Why use fiberglass tape when you can cut strips from fiberglass cloth? Because this specially treated 6 oz. tape has selvaged edges that will not unravel when wetted out, making application easier, neater and faster. Fiberglass tape is used for protecting planking junctions and in Stitch and Glue construction for reinforcing joints. Sold by the yard.
Note: For higher-speed stitch and glue hull designs junctions, the plans frequently call for cloth cut on a bias (at 45°) or Double Biased cloth. Using cloth installed at 45° to the axis of the junction allows all material to reinforce the joint as opposed to half reinforcing the joint and half running parallel to the joint.
If you're unfamiliar with fiberglassing, we suggest our "How to Fiberglass Boats" book and DVD.