This large classic 20 inch empire is a knife pleat. Narrow bias finish the top and bottom.
Please know too, once you buy an illume lampshade, the liner is guaranteed for life. If for any reason the lining tears or disintegrates, we will replace it free of charge. Just bring it back and we'll get it done for you.
The measurements are 11 inch diameter top, 20inch diameter bottom, and 14inch side with a nickel washer spider.