Posted on May 02 2017
If you are shopping for new quilts, you might come across the term “tog rating”. What does “tog” mean and does it make any difference to your final choice of quilt (duvet)? Read on to find out the answers to these questions and more….
Tog is a measurement of thermal resistance which is used mainly in the textile industry, particularly for carpets…and quilts. The tog measurement system was invented in the 1940s by the Shirley Institute in Manchester, England. The Shirley Institute focused on research for the cotton industry, which played a vital role in the economy of the country during this period. With the tog rating system, they aimed to offer an easy, consumer friendly way to describe how much insulation and warmth a fabric would provide.
A common misconception about the tog system is that it can tell you how thick a quilt is or how much it weighs. This is incorrect because different types of quilt filling offer different levels of insulation. In practice, this means that goose-down filled quilts may be lighter than a quilt of the equivalent size, filled with duck feathers, but provide a lower level of insulation, therefore achieving a lower tog rating.
When shopping for quilts, your first consideration should be whether you need a high tog style, to keep you warm in winter, or whether a lower tog will be sufficient. Some brands offer a two part quilt set, a practical option which allows you to clip two layers of quilt together to create a higher tog in winter, or use only one layer in warmer weather. In general 4.5 tog quilts are considered to be lighter and cooler, so more suitable for summer, while 12 – 13.5 are at the higher end of the scale, for winter use.
In Australia, quilts are usually sold by weight instead of by tog rating. There is no direct formula for converting weight to tog rating, however, product manufacturers usually offer suggestions as to whether the quilts are more suitable for summer or winter. Light summer-weight quilts start at around 250gsm, while the heaviest winter-weight quilts are around 750gsm.
Source: Written for Just Bedding by Claudia Vilches.