Originally Posted by
bearisgray
It makes sense to use the tools that make the job easier.
No point in getting a back-hoe for a job that a shovel would be more efficient.
Love this analogy! I have a 16.5" but frankly, rarely use it. Had to buy it for a class and have maybe used it a couple of times since then.
I square up my units as I make them so rarely have a need to use a larger ruler just to square up a block. But as others have mentioned, buy a) what you can afford and b) the next size up from the most common size block you make. To square any unit, I measure from the seam line in the middle of the unit/block to the outside edge and trim as necessary.
My other other suggestion is to make sure that you buy the same brand square up ruler as the rest of your rulers. They are not all created equal. If you use brand x to do your primary cutting/measuring and brand y to square up - they measurements may not be consistent. You would think an 'inch is an inch' but it isn't.