Smooth Panels - Imperial
Imperial's Smooth Panel vases are technically stretch glass and not carnival glass as they were introduced with other Imperial strectch glass in the 1910s and 20s. But they are iridized, formed in a mold and they do have a pattern of eight interior panels so many carnival glass collectors have them in their collections.
Imperial's Smooth Panels vases are found in four different base sizes and various colors. They have 8 subtle panels on the interior and a collar base. Just above the base is an indentation followed by a horizontal line. The photo on the left shows each base size; The smaller 2 1/2 inch bases are in the front row in smoke on milkglass, marigold/clambroth, and marigold on milk glass. The vases in the back row are a 3 1/2 inch in teal, a 4 1/2 inch in white, a 3 1/2 inch in wisteria and a 5 1/2 inch in marigold. The photo on the right shows vases, all with a 3 1/2 inch base, in the various colors to be found in Smooth Panels: red, teal, smoke, wisteria, amber, clear, white, marigold and purple.
When sold, auctioneers only sometimes mention the base size in addition to the vase's height. It can be difficult to tell the base size from just a photo.

The photo to the right shows the vases' collar base and the horizontal line just above the collar of this amber vase.
Imperial Glass gave a mold number to each base size: 692 is 2 1/2 inch bases, 693 is 3 1/2 inch bases, 694 is 4 1/2 inch bases and 695 is 5 1/2 inch bases. Only pieces sold under these four Imperial mold numbers are true Smooth Panels pieces. Each base size can have multiple heights due to the amount (if any) the vase was "swung".
Vases with a base size of 5 1/2 inches are referred to as "Funeral Vases". The photo, at left, shows a Red Smooth Panels Funeral Vase.

There are wheel-cut versions of Smooth Panels vases as shown in the photo on the right. Vases that are not swung but flared out are called bowls or "sweet pea" vases as shown below.
Most Smooth Panels vase have no pattern in the base but occasionally the bases have a star in them.

Most vases are not signed with an Imperial Iron Cross but some are found with this mark on the inside bottom. This mark can be found on vases with or without a starred base.