Below is the list of tables from the database along with their columns and datatype. Need to generate an accurate SQL query for the question.
Only use the columns present in the respective table. Only use the columns which are required to generate the SQL query. Only use table joins if required and not otherwise.

### Tables ###
TABLE: CREATE TABLE table_1307572_1 ( composition VARCHAR, edge VARCHAR )

### Question ###
What material is made with a rounded, plain edge?

### Accurate SQL ###

SELECT composition FROM table_1307572_1 WHERE edge = "Rounded, plain"