A Box Template for the Padded Flat Rate Envelope

I’ve been making boxes, and “upped by game” by using a ruler and measuring out my cuts. This saves a lot of time!

This article figures out the dimensions of a small box that will fit into a USPS priority mail padded flat rate envelope.

Believe it or not, for years, I cut boxes by placing the object onto the cardboard, and then tracing out the dimensions.  It works, and well, but turns out to take a lot more time than I realized.

By measuring and then drawing out a pattern, I can cut a box in under ten minutes. If I use a template, it’s even faster. I haven’t measured it yet, but I suspect it’s around two minutes.

So, I decided to make a pattern for a box that fits into a padded mailer, or vice versa – a box that will hold a padded mailer as protection.

Before I go on, if  you really need this, you can buy premade boxes called Scotty Stuffers that will also serve the same function. I found them while I was researching what I’d just done.  They cost a little less than a dollar, which is pretty good for a box.

How to design it?  Well, I measured a padded mailer, and it’s around 9 x 12.5. The total circumference for the opening is 18 inches (2 x 9 inches), so the total length of edges is also going to be 18 inches.

That’s a rectangle of 8 x 1, 7 x 2, 6 x 3, or 5 x 4, or 4.5 x 4.5. (I’ll ignore 8 x 1 going forward.)

There are almost 25 inches to work with, going down into the envelope, but the edges need to match the cross section. So the depth is constrained.  I’ll just say it’s 24 inches, because that’s easier to divide by 2, and it’ll make closing the flap easier.

With a 7 x 2, you need one edge to be 2 inches. The maximum depth is  (24 – 2 – 2 ) / 2 = 20 / 2 = 10 inches.

So a 10 x 7 x 2 box fits.

A 9 x 6 x 3 box fits.

A 8 x 5 x 4 box fits. (This box will fit some mugs.)

A 7.5 x 4.5 x 4.5 box fits.

Note that the last two dimension are the constraint. You get some leeway with the depth, but the object must fit into a box with one of those above crosssections.

The weight of cardboard to make these boxes is around 5 ounces.

Shipping glass in these boxes may work, but it won’t be covered by insurance if it breaks. The insurance says they want 2 inches of padding on each side, and a box within a box.

Author: John

I can be reached at johnk@riceball.com.

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