EZ PROFESSIONAL BALLOON DANCE FLOOR CANOPY MADE WITH BOSS 4" SPACES NETTING B.O.S.S. ....Big Over Sized Spaces Netting. Quick steps summary: With BOSS netting simply count every 1 2 3 spaces over, add a balloon, and repeat to make a Perfect Balloon Canopy. You get a symetrical evenly spaced professional looking and stable Balloon Canopy ideal for indoor and OUTDOOR USE! A special new 4" hole size netting die was made just for YOU, Professional Balloon Decorators, to make life EZ for you. So enjoy! step by step details: 1) Open netting and stretch top end corner to corner. If available, fasten temporarily to comfortable working height on two column base stand poles. Otherwise, stringing net between two chairbacks to start with will work fine. 2) Use Holey Box Balloon sizer box 10 or 10 1/2" SIZE hole to make all 11" balloons the same size for a professional and uniform look. CLIP or tie first balloon to first top corner square of stretched out netting. Skip two spaces, add another ballon and repeat till top row is filled with balloons. Alternate theme balloon colors, 1,2,3, or 4 colors. Keep repeating same color pattern. 3) Repeat for second, third and all rows till complete. BUT at connector rows of netting, where two pieces of netting need to be attached, simply tie or clip the balloon to both edges of two connecting netting squares. This lets you make a canopy as big as you like. Just keep attaching pieces as needed. 4) For indoors, tie four corners to anchor lines and anchor other ends to floor weights or balloon columns. Wrap free end of anchor line in and around two or so clusters of balloons columns till secure. BUT for outdoors, Weave anchor line in and out along entire edge of two parralel sides of canopy. Secure corners of canopy net to the stretched out line so they do not "ride up" the line. Then anchor loose ends to columns or bases that are heavily weighted or fastened to the floor. THE MATH: A BNP17 size net holds 19 x 15 rows of 11" balloons = 285 balloons. For a square 15x15 = 256 11" balloons. Add 144 11" balloons if you make 4 of the 6 foot spiral colums with 4 balloons per cluster and 9 clusters per column. So, plan on 256 to 300 balloons for a basic canopy held in place with 4 lines to weighted bases on the ground. Or with spiral columns at 4 corners, 400 to 439 balloons depending on your final size. I'd bring 500 balloons just to be safe and consider using extras on table centerpieces.