What do you mean by legal standards? How many specifications are there for the legal scale?

The legal measure of a book refers to the square measure of the work.

Four feet means four square feet.

The standard four-foot rice paper is eight square feet.

Four square feet can be four square feet (69*69CM).

About 2*2=4 square feet

It can also be a four-foot banner (34* 138CM).

Approximately 1*4 feet =4 square feet.

There are 33.3*33.3CM as square feet.

There won't be much difference between up and down.

Specification of ordinary rice paper (unit: cm)

Three feet: 50* 100

Big three feet: 69* 100

Four feet: 69* 138

Five feet: 84* 153

Six feet: 97* 180

Eight feet: 124.2*248.4

Zhang Er: 144.9 * 367.9