In order to get a clean, sharp edge when applying a second paint color, the first had to be masked, of course, and this required that newspaper or butcher paper be fastened to the car body. If shop-brewed glue was used, it would sometimes stick so well that it had to be scraped off, more often than not pulling paint with it. Surgical adhesive tape was sometimes employed, but its cloth backing tended to absorb solvents from the newly sprayed paint and cause the masking materials to stick to the paint they were intended to protect.

—The Evolution of Useful Things,
Henry Petroski

How does this paragraph help develop the central idea?

It shows that shop-brewed glue did not stick well to the paint.
It shows that early attempts at finding the correct stickiness failed.
It shows that surgical adhesive tape was the ideal product to use.
It shows that cloth backing was better than paper backing for glue.

Question

In order to get a clean, sharp edge when applying a second paint color, the first had to be masked, of course, and this required that newspaper or butcher paper be fastened to the car body. If shop-brewed glue was used, it would sometimes stick so well that it had to be scraped off, more often than not pulling paint with it. Surgical adhesive tape was sometimes employed, but its cloth backing tended to absorb solvents from the newly sprayed paint and cause the masking materials to stick to the paint they were intended to protect.

—The Evolution of Useful Things,
Henry Petroski

How does this paragraph help develop the central idea?

It shows that shop-brewed glue did not stick well to the paint.
It shows that early attempts at finding the correct stickiness failed.
It shows that surgical adhesive tape was the ideal product to use.
It shows that cloth backing was better than paper backing for glue.