Let’s talk tape. In 2015, I wrote about my favorite “sort of sticky” tapes for labeling and repairing things [Tape Op #107]. Recently, I needed to measure the diameter of a mic, so I wrapped “sort of sticky” artist tape around the mic and marked the tape at one full turn. After removing the tape and re-sticking it to a flat surface, I was able to measure my marks for circumference. A quick division by π resulted in diameter. That’s when I thought, “Wouldn’t it be cool to have a tape measure that’s marked in units of diameter?” I found two on Amazon, both made by Perfect Measuring Tape Company perfectmeasuringtape.com. I ordered the cheaper DCT79 model ($3.99), which is a compact, watch-sized, self-retracting metal tape, with keychain attached. The topside of the tape is marked for standard linear dimensions, in both inches and cm, while the underside is marked for diameter. You wrap the tape around whatever you’re measuring, and the numbers on the underside correspond to diameter — no math required. The underside scale doesn’t start until a couple inches from the hook, so you need slightly more than one full wrap to obtain a measurement, but this increases accuracy, since the hook doesn’t get in the way of the measurement. Speaking of the hook — on standard tape measures, the hook “slides” by a slight amount to account for its thickness when measuring “outer” (hook pulled from a corner) vs. “inner” (hook pushed against a surface) dimensions. Because the DCT79 is equipped with a smoothly bending, non-arched tape that won’t snap flat on its own, it’s really meant for outer measurements, so its hook is fixed. Note also that a non-arched tape is better for marking the surface you’re measuring. Say, for example, you’re building a frame for an acoustic panel, and you need to cut an exact length of wood. A standard arched tape requires you to “rock” the tape to one of its edges to precisely mark the wood at the desired length, a motion that can annoyingly unhook the tape. In my workshop, I have a heavy-duty, non-arched tape for that reason — the FastCap PMS-FLAT-16 FlatBack Metric Standard fastcap.com ($9.59). Like the DCT79, the FlatBack lays flat for making precise markings, but it also has several other unique features: a second button just underneath the mouth of the tape that momentarily slows/stops tape retraction (in addition to a standard lock above the mouth); a built-in pencil sharpener and an erasable side-panel for notes; a matte finish on the tape that also takes pencil marks; and a “levered” belt clip for effortless attachment/removal. All these features make the FlatBack my top choice for the workshop. The FlatBack isn’t designed for inner measurements, but FastCap makes “arch-back” models too. I also recommend the Komelon Evolution series komelon.com; the PSE55E Metric Standard ($10.66) is my go-to for the toolbox (vs. workshop). It’s push-to-retract, which I prefer over push-to-lock. It has inch and cm markings on both sides of the tape, which means you can very easily push the hook onto the floor, then feed the tape up to the ceiling, and the tape will snap into vertical position so you can read the ceiling height (or doorway, etc.) on the underside of the tape. (Try this with a standard tape measure — the tape will stand more rigidly when its underside is toward you. Unfortunately, most tapes have blank undersides.) Moreover, the hook is two-sided, so you can hook the backside of the hook, read the measurements on the underside of the tape, and mark whatever surface you’re measuring without having to rock the tape.(Now, don’t get me started on my collection of laser measurement tools.)

Tape Op is a bi-monthly magazine devoted to the art of record making.

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