Roger and Claudia Hardy, authors of "The Complete Line of Akro Agate Co.," included photos of these bowls in their book. However, when we visited with Roger Hardy in Clarksburg, W.V., in March 2010, he told us that he no longer believes Akro Agate made these bowls.

He said his original information came from one former employee and that he has since found recollections such as those to not always be accurate. He also bases his opinion on the fact that with their enamel-fired color over a translucent white base, they do not look like any other ware made by Akro Agate and that, in fact, they do much more closely resemble products made by Hazel-Atlas, a glass manufacturer also located in Clarksburg, WV.

Therefore, please consider that the manufacturer of these flips is unknown, with the possibility that they were made by Hazel-Atlas. (However, Akro Agate did make at least one ribbed flip from slag glass, similar in shape to these, because it is on display (shown above) in Hardy's museum of Akro Agate glass and before that sat for years on the desk of the secretary in the Akro Agate plant.)

These flip-top containers were made in two sizes. Unlike most of the flip-tops, it is unusual for these lids to be pressed on; most can usually be twisted off for cleaning.

The flips above, in blue with enameled green lid and yellow with enameled orange lid and below with hot pink lid, were sold under the Pantry Pops household line, marketed by GEMCO-WARE. In addition to the flips, syrups and a variety of salts and peppers, there were also oil and vinegar cruets and sugar pourers.

We feel certain that the following flips were all made by the same company as the rest on this page, whoever that might have been! There are three flips with straight sides, in white, black and clear, and their enamel quality and texture seems to be just like the flips shown above.

Frequently these flips show their wear through small chips of the color on the ribs, and these below chip in exactly the same way.

In addition, all the flips below have single-digit numerical mold marks that appear to be exactly the same size and font as those above. (See the photo below of the white mold mark, a 1.)

The three flips immediately below are all 3 3/4" x 4", and their lids were made by either MEDCO or GEMCO.

The flip below - or one just like it - was featured in a Season 1 episode of "Mad Men" when Betty served coffee to her neighbors in the Ossining 'burbs. It measures 4 5/8" x 3 1/8" and has a unique swirled design. We think it's made by the same manufacturer as the rest on this page because of its size, its lid that twists off and its single-digit mold mark on the bottom - in this case, a 4.