O.D. Vs I.D. Measurements

As you go through the IMPAK Corporation product catalog, you might notice that the majority of our products are listed by their Outer Dimensions (O.D.). This is an important detail to remember because some industries are used to thinking in terms of the pouch Inner Dimensions (I.D.). While this is generally an easy way to ensure ample space in the pouch, it can lead to a lot of wasted material with the added material on the sides. By starting at O.D., we keep the pouches a uniform size without wasting as much material.

Why use O.D. vs. I.D.?

The outside dimension refers to the measurement of the widest point of the pouch, usually from one outer edge to the opposite outer edge, passing through the center. O.D. is essential for determining the overall size of the pouch, including its width and how it will fit within a larger system or packaging.

The inside dimension, on the other hand, refers to the measurement of the innermost part of the pouch, from one inner edge to the opposite inner edge, passing through the center. I.D. is important for understanding the capacity of the pouch, as it helps determine the available space inside for holding and storing items. When it is crucial for a product to fit snugly inside a pouch, one must be sure of the pouch's I.D.

Obviously, the width of the side seals on a pouch is related to its I.D. and O.D. Two pouches may have the same I.D. but differing O.D. measurements due to a difference in side seal widths. Most bags are made with side seals of 1/4" to 3/8", but side seals can be up to 3/4" wide or more. It may be desireable for a pouch to have an unusually wide side seal if the I.D. needs to fit a product exactly and the O.D. needs to be a specific measurement for the sake of printing or container size.

What about printing?

It's important to consider both O.D. and I.D. for custom print purposes. O.D. provides the total surface area available for printing graphics, logos, text, or any design elements. A larger O.D. provides more space for creative and informative printing. But in order to ensure accuracy in printing, I.D. must also be factored in, to account for the potential challenges associated with seams and edges. Proper registration of the printing equipment requires precise measurements of all pouch dimensions to ensure that the design is aligned correctly.