Tek Tip - Understanding Polyester Film Tolerances

Performance consistency is an often unappreciated benefit of Melinex® & Mylar® polyester film from Tekra. Perhaps, the most commonly overlooked performance characteristic is that of gauge tolerance.

Polyester manufacturers like Mylar® Specialty Films (formerly DuPont Teijin Films™ (DTF)), monitor & control several key film attributes during the manufacturing process. Gauge is just one such variable. For most interested suppliers to the PET industry, the process of how gauge tolerance is achieved is of less importance than the result.

For MSF (formerly DTF) polyester films, below are the production tolerance guidelines for two randomly selected film type / gauges of Mylar A: 200 (thin) vs 700 (thick):

Mylar A / 200:

  • Nominal gauge = 200 (2 mil)
  • Target gauge = 197 (1.97 mil)
  • Range = 189 – 205 (1.89 – 2.05 mil)
  • Tolerance = +/- 4%

Mylar A / 700:

  • Nominal gauge = 700 (7 mil)
  • Target gauge = 690 (6.92 mil)
  • Range = 662 – 718 (6.62 – 7.18 mil)
  • Tolerance = +/- 4%


The basic range of gauge tolerance for MSF (formerly DTF) polyester film types does vary amongst product film types. However, film thickness is more a determinant in gauge tolerance than that of product film type. Applying this logic, gauge tolerances are basically the same for clear, matte vs white PET. What does differ in this stated example however, is the density factor of these film types (i.e. white PET is less dense).

Tekra has nurtured customer idea innovation in Melinex & Mylar polyester films from MSF (formerly DTF) for more than two decades. Should you have a specific film type request where gauge tolerance is at the center of importance, contact one of our customer service or sales experts for guidance. We look forward to the opportunity to serve you!

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