Guide Gear 12x12 Tarp as modified

I bought a Guide Gear 12x12 tarp for about $20.00 in early 2011.
The weak points of the Guide Gear tarp (12x12) are that
A -  it lacks loops in the middle of the sides so it can be hung in a rectangular set up,
B  - lacks sufficient anchors for the panel pull loops located on the three seams across the panel, and panel pulls are stitched only to the panel seam,  and
C  - the side pull/tie down loops around the exterior seam are only single stitched. 

Photos show inside and outside of panel pull

We modified the tarp right after it arrived: (and by "we" I mean my wife)

Additional Materials:

Guterman 100% Polyester Sew-All thread
One third of a yard of black rip-stop nylon

MOD 1  -- Additional Loops.  We put 1.5” loops in the center of two sides to allow a rectangular set up.

We sewed the 1’” wide rainbow strapping onto each side of the tarp material and then reinforced that area with rip-stop nylon triangles that were cut from 12” squares. The hypotenuse along the outer seam of the tarp is about 17”. Then we box stitched the strapping to again reinforce the connection.

MOD 2  --  Added Anchor Points.  We put 6” square rip-stop nylon anchor patches on the inside under the panel pulls on each short seam. We then box stitched the factory installed loop using a box that is 1/4” wider than the existing seam.
We put 3” square anchor patches under the 3 loops on the center seam and made the same box stitch of the factory loops. 3" and 6" Panel Pull and anchors

We also reinforced the center seam stitch of the loop through the factory seam.

detail of box stitch reinforcements.

MOD 3  --  We went around the exterior seam and double stitched each factory installed loop so that the added stitching went through the factory sewn seam to reinforce each exteriors pull loop. The blue thread is what we added as extra reinforcement at each tie down loop.

I seam sealed the new stitching. For around $30.00 we now have a very versatile, strong tarp. The Guide Gear tarp is 100% Polyester coated with polyurethane and the seams are factory taped.   Below are some photos of the tarp rigged in some different configurations.