Plain White Undecorated Opal Pyrex

From the 1950s to the 1980s only a few shapes & sizes were offered in plain white opal Pyrex.  But any decorated piece can become an undecorated one by removing the decoration.  Dishwasher fading is the main reason for loss of colour and shine, and items with white patches and rough scraps of paint are numerous.  It is only natural that the owner of an item like this might recognize that it is still perfectly functional, but the damaged exterior is unsightly.  Concluding that it would look much better plain white, some decide to remove the remaining paint.

Most often their intent is to improve the appearance of an item that they want to continue using, and people do admit to doing this.  It arises from an effort to save an old favourite rather than throwing it away because it has lost its original beauty.  Of course it is dishonest to strip Pyrex with the intention of selling it for profit because it is "rare".  But a stripped piece found in a thrift shop for a trivial price hardly represents an attempt at fraud.

Genuine Opal 022 (1 Qt) & 023 (1½ Qt) round casseroles.

Even without deliberate intervention, an item can become completely white after thousands of trips through the dishwasher.  When this is the case, there might be traces of paint in crevices, or the outline of a pattern might still visible under the glare of a bright light.  It is worthwhile to inspect an item closely for any clues of previous decoration, but if it has been carefully cleaned up on purpose, there could be no visible evidence left at all.

An unappealing faded piece can become gleaming pristine "Opal" once the patches of dull paint are taken away and the normal shine of the glass is revealed.  It is a myth that the glass itself will always show proof of dishwasher damage.  Harsh chemicals that ruin a fragile coloured finish will barely register on the surface of opal Pyrex.  This type of glass was formulated to be resistant to attack from both acids and alkalis.

Some Pyrex dinnerware, nesting bowls, casseroles and baking pans were adorned simply with a gold band.  Gold trim is less durable than coloured patterns, and it can disappear even if it has been consistently washed by hand.

Regarding Corelle, Suprema, Corning Ware and Centura, patterns on these products are much more durable and might begin to fade only with extremely harsh treatment.  Among this grouping, a former decorated piece being stripped clean is very unlikely.

In addition to Winter Frost White Tabletop Ware, the shapes & sizes listed below are genuine examples of plain undecorated opal Pyrex originating from the company.  For shapes & sizes not mentioned below, if they look plain white now, then they were probably decorated when they were new.

Opal nesting bowls, two 401s & one 402, with blank backstamps.

400-Series Round Nesting Bowls: 
Available during 1954 & 1955, plain white 400-series nesting bowls were called an Opal Bowl Set.  The peculiar feature of these bowls is the absence of a backstamp; there is no brand name, model number or capacity marked on the bottom.  What might be on the bottom is a one or two digit mould number, but this could be absent too.  Any 400-series bowl that does say "Pyrex" on the bottom would have had some kind of decoration originally, either patterned, solid-coloured, or gold-banded.

Exceptions:  A small number of turquoise-patterned 401 & 403 bowls also have blank backstamps.  A 403 with a small diamond design was combined with a 624 lid and a cradle.  A 401 & 403 equipped with a bracket were named Hot 'N' Cold Chip and Dip, and their pattern is a series of pointed oval shapes with starbursts in the centres.  Many bowls from these two sets are blank on the bottom, but some have regular markings too.

501 & 502 Refrigerator Dishes:
Plain white 501 & 502 refrigerator dishes were manufactured at some point, and like 400-series bowls, they also have blank backstamps.  There should be no brand name, model number or capacity embossed on the bottom of these items, but a mould number might be present.  It seems that a true Opal 503 does not exist, but if it does, it should have a blank backstamp too.

Opal 502 refrigerator dish.  There is only a mould number in the space where a backstamp should be.

022, 023, 024 Round Casseroles:
In the early 1980s, 022 casseroles with utility lids were available in plain white.  This size does not exist with any patterns or solid colours, so all plain white examples are sure to be genuine.

On at least three separate occasions between 1956 & 1959, plain white 023 casseroles were sold in special sets with a utility lid and a metal cradle.  An Opal 023 has all the usual markings, with brand name, model number and capacity on the bottom, identical to solid-coloured or patterned 023s from the same period.  The Opal ones were popular, so the chances of a plain white 023 being authentic are very good.

A small number of undecorated 024 casseroles were topped by boldly patterned clear utility lids.  The lid designs are mainly gold-leaf accented with other colours, and might be from the 1960s.  These are very uncommon, so a plain white 024 that does not come with a decorated lid is more likely to be a stripped one.

Opal 023 (1½ Qt) round casserole with 683 utility lid.

575 Space-Saver Casserole:
Like 024 casseroles, a few plain white 575 2 Qt Space-Savers were available with colourful gold-leaf patterned clear lids.  These sets are also very uncommon, so without a specially decorated lid, a plain white 575 is probably a regular patterned Space-Saver that has been stripped.

1063 Divided Dish:
In the early 1960s, 1063 divided dishes were offered in white opal and blue opal.  The latter choice was named Bluebelle.  American-made 1063s were never decorated, so any plain white one that is marked "Made in U.S.A." is truly Opal.

Exceptions:  This shape was also produced in the United Kingdom, marked either with the JAJ brand or with a crown logo and "Made In England".  They were also sold plain white, but some are printed with a Wheatsheaf pattern in coral (red) or green.

Opal 1063 divided dish, U.S.-made.

Baking Pans:
During the early 1980s, a selection of bakeware was available in plain white.  Alongside 022 casseroles were: 221 round cake pans, 213 loaf pans, 228 Flavour-Saver pie plates, flat-rimmed 209 pie plates, and possibly others too.  These Opal items can be authenticated by their modern backstamps, with measurements in Metric and an approval for microwave usage.  In the time frame that these markings were used, these shapes were not produced with any patterns or solid colours.

In general, older opal Pyrex baking pans were not sold without some type of decoration.  One exception is a 215 loaf pan, which never seems to appear with a decoration, always plain white.  Nothing else is known about it, but it is marked in inches (9 x 5 x 3) rather than Metric, so it might be older than the other Opal baking pans.

Opal 221 cake pan.  Its backstamp states the size as "21 cm" and also says: "For oven and microwave".

Bowls for Electric Mixers: 
In co-operation with small appliance manufacturers, Corning produced plain opal Pyrex bowls designed for electric stand mixers.  These brands include Hamilton Beach, Sunbeam, Westinghouse, General Mills (Betty Crocker), General Electric, and possibly more.  The bowls often came in two sizes, and small ones typically have a spout and large bowls do not.

Each brand of mixer used a different bowl shape, and some were made of clear Pyrex too.  At times, other companies were hired to manufacture the same bowls.  So the identical shape might be found in Pyrex as well as another brand of glass, but the name of the glassmaker is not always present either.

Bowls for a Westinghouse mixer, capacities approximately 1½ Qt & 4 Qt.  Marked "Pyrex For Westinghouse".


Related Articles: 

Pyrex Model Numbers
What are mould numbers & model numbers?
1960 Pyrex Catalogue: Part One, Part Two
1961 Pyrex Leaflet 
Extra Photos: British Pyrex