a) Arches are a fun and popular balloon decoration with endless potental for creativity
Arches add excitement and provide a lavish dispaly of color
There are many variations...
the following is just a sampling of the simple ways arches can be consrtructed:

Single Arch - made up of single latex balloons tied directly to a monofilament ( fishing line)
The ballons can be packed together or evenly spaced
The arch can be  dressed up with a variety of accents - such as ribbon, tulle, poly-silk leaves, fresh or silk flowers, feathers, OR...
An air-filled latex balloon can be tied directly below the helium-filled balloon, creating the High-Low Arch - a variation of the single arch
LINK-O-LOON® balloons can be used to easily create this simple but elegant arch

Rainbow Arch - includes several single arches of varying lengths that can be placed together, creating a rainbow of colors 

Swirl Arch - composed of either a three or a four cluster latex group joined together by paper clips or Twist Klips TM  and attached directly to the monofilament line

Foil Arch - can be created using helium-filled foil balloons

Swag Arch - an air filled arch that can be suspended from the ceiling or other support
It can be a Single or Swirl Arch
The ballons can be attached to the monofilament line, using a pipe cleaner twisted around the stem

formulas used to calculate approximately how many balloons are needed for a spiral arch:
  5 inch = 12 per foot
  9 inch =   8 per foot
11 inch =   6 per foot
14 inch =   4 per foot
16 inch =   4 per foot

 

b) Link-O-Loon balloons

LINK-O-LOONS®