Feeler gauges - recommendations?

Philtre

I'll be getting some feeler gauges to measure action heights and so on. Which ones are good and how many do I need practically?

Nomad

I would say that you don't necessarily need anything fancy, but a set that has a good range of sizes can be worth having. With cheaper ones that have less sizes, you get around the missing sizes by opening whatever two or three blades add up to the size you want, and that can be a bit more fiddly to handle sometimes because you're trying to .slip however many layers into a thin gap - can be tricky if the ends are at all splayed, while a single blade will work properly as a feeler.

One thing to watch out for is so-called metric feeler gauges that are actually imperial that have both metric and imperial sizes etched on them, meaning the metric sizes are silly numbers (accurate numbers, but silly numbers if you think in metric).

The set from Crimson Guitars has a very good range of sizes, especially the thin ones (lots going up in 10 micron steps). On the downside, they're quite pricey, and it's debatable whether they're as easy to use because they're quite long (about double the length of the typical mechanical sets). They're also held in a wooden frame rather than the more usual metal, although it does seem durable.

Maynehead

These are the ones I'm using. Been using them for years and they've been great. Keep them oiled and they'll last for many more years I'm sure.

https://www.ebay.co.uk/i/282001894987