In modern clothing and fashion design, a button is a small fastener, now most commonly made of plastic, but also frequently of metal, wood or seashell, which secures two pieces of fabric together.

Ligne is a French word meaning "line" and it is abbreviated with the letter L. Internationally, ligne is used to recognize button size. Ligne is a liner unit (1/40 inch) used to measure diameter of buttons. Usually watchmakers, button-makers and hat-makers use Ligne to measure their product size.

Before calculating button line we should know following measurement: 

• 1 inches = 40 ligne = 2.54 cm,

• 1 ligne = 0.635 mm

 

Flat buttons that have 2 small holes in the center to sew through. The holes are typically lined up parallel to the edge that it is fastening.

 

Flat buttons with 4 holes in them. The attachment is stronger that with 2 hole buttons and they are better for thick fabric.

 

Have a hole  or loop at the back through which it can be attached. They are better when attaching to a loop rather than attaching 2 pieces of fabric together. They also make great eyes.

 

Plastic domed buttons that allow you to cover with whatever fabric you choose so that you can match it to your project. These work well with upholstery and home decor projects.

 

Knobs made of knotted strings that pass through a loop to fasten. They are very decorative, and do not require a button hole

 

Made by embroidering or crocheting tight stitches over a form, such as a cabone ring.

 

Typically plastic and unusual shapes (such as anchors, flowers, or animals) or have designs printed on their surface.

 

No Sew buttons to replace broken waist fastenings. They attach to the fabric with a pivot tack that stays in place, making the separation between the button and the fabric much wider. This allows room for a thicker fabric to be attached and a stronger attachment to the fabric that can deal with more stress.