Nice article from Smithsonian covering spider web production and construction.
The material—spider silk—has chemical properties that make it lustrous, strong and light. It’s stronger than steel and has impressive tensile strength, meaning it can be stretched a lot before it snaps. Scientists have been trying for decades to decode exactly what gives the silk both strength and elasticity, but so far they have found only clues.
Any individual spider can make up to seven different types of silk, but most generally make four to five kinds, says Jonathan Coddington, director of the Global Genome Initiative and senior scientist at the Smithsonian’s National Museum of Natural History.
Spiders use their silk for several purposes, including web-building. That diversity is not hard to imagine, given that Earth hosts 45,749 species of spiders, according to the World Spider Catalog. The number is changing constantly with the frequent discovery of new species.