Stems

• #2 - 2 mm diameter, 40 cm / 15.75 inches long, for small to mid size flowers
• #3 - 3 mm diameter, 40 cm / 15.75 inches long, for large size flowers like peony
• #5 - 5 mm diameter, 80 cm / 31.5 inches long, for sunflowers

Wires
Colored wire is used to construct the frame of the flower and the leaves. The wire used for nylon flowers comes in different thickness (gauge): 20, 22, 24, 26, etc. The higher the gauge number, the thinner the wire.

#22 through #26 gauge colored wires are made with a thin layer of plastic (mylar) on the outside. They come in a several colors -- silver, gold, red, green, and pink.
White wire is made with a paint coating, and is currently available in #20, #22, and #24.

The lower gauge wires (#20, #22) are generally used for thin flower stems or leaf stems, and for making larger flowers and leaves. The thinner (#24, #26) wires are more flexible and are most suitable for making flower petals and leaves.

Stem Wire is made with a thicker wire which is wrapped in a thin green paper. Note that the size numbering is also different, with #2 wire smaller than #3.

Wire Gauge Conversion