In the early 1970s, Corning launched a full-line of PYREX Compatibles to coordinate with Corelle Livingware patterns. The first salt and pepper sets in the PYREX Compatibles line, all launched in 1972, were Spring Blossom Green, Butterfly Gold, and Snowflake Blue. When these items made their debut, salt and pepper sets were sold in white, applied to clear glass, with the matching design. The white paint, which was prone to chipping, was replaced with clear glass in 1975.

The white background was available until 1974 on Spring Blossom Green, Butterfly Gold, Snowflake Blue, and Old Town Blue. Old Town Blue was somewhat unique in that the PYREX tabletop items did not have a line of matching PYREX mixing and bakeware sets. However, marketing materials after 1976 advertised that Old Town Blue was an ideal companion to the newly released PYREX Homestead pattern.  
 
White Background S&P Sets 
Spring Blossom Green: 1972-1974
Butterfly Gold: 1972-1974
Snowflake Blue: 1972-1974 
Old Town Blue: 1974

In 1975, the new clear background replaced the white background on Spring Blossom Green, Butterfly Gold, Snowflake Blue, and Old Town Blue. Snowflake Blue with a clear background was only available in 1975, the year in which the pattern was discontinued. Autumn Harvest, although not a PYREX Compatibles product line offered tabletop ware, including a clear salt and pepper set from 1980-1983.  
  
Clear Background S&P Sets
Spring Blossom Green: 1975-1983
Butterfly Gold: 1975-1983
Snowflake Blue: 1975 
Old Town Blue: 1975-1983
Woodland: 1978-1983
Autumn Harvest: 1980-1983

Interesting and unique PYREX items are always a favorite with collectors and dealers alike. Many collectors are most intrigued by PYREX with a twist: items that have a design or pattern from one product line that appears on the solid-color bowl from a different product line. Few collectors are lucky enough to have stumbled upon (or paid a hefty price for) these rare items.

One example of PYREX with a twist is the Green Woodland 4 Qt Cinderella Bowl (444). This bowl has the standard Woodland design normally produced on a dark brown background. However, this bowl has a dark green background – most likely the green background used during the same time period for Spring Blossom Green.

So, what exactly are these items and where do they come from?

Many items come from online sellers in Charleroi, Pennsylvania, whose family members worked for Corning Glass Works during the years of opal PYREX production. The items were most likely production mistakes which occured during the transition of manufacturing one product line to the next. Since most "PYREX with a Twist" items come from Charleroi, PA, it's possible that plant workers brought home these "mistakes" or perhaps they were even sold in a company store at a discount.