I have heard how important it is to use the same ruler to complete a project, but who wants to use a big long ruler when subcutting a piece into little pieces.

Is it okay to use different sized rulers made by the same company? Are the measurements consistent within the company?

Compare your rulers - if they're different, I would not use them both for the same project. I've talked to lots of quilters who will not use the gridded cutting mats for measuring because the grids are not accurate - I've measured mine and I'm happy with it.

I did discover that 2 of my rulers are NOT accurate on 2 sides. Thankfully, I was drawing lines on paper, not cutting fabric, when I discovered this. They're about 1/16th of an inch too large, which WILL add up! Now that I know this, I make sure I don't measure on those sides.

gridded cutting mats = the thing you lay your fabric on and not a "gridded" ruler???

yes, the grids on your cutting mat :D

I will compare my smaller ruler(s) with my larger one(s) and then if they match up I am comfortable using them all on the same project :D:D:D

Honestly, I've never heard that about rulers. I use many different rulers doing my projects and I've never had a problem.

A lot of people (me included) don't like the rulers that have a wide yellow line printed around a thin black line. If you measure at the outer edge of the yellow line instead of the center of the black line, you'll be a couple of threads off, which doesn't sound like much, but added up over several blocks, it will make a difference. I think those rulers make it hard to see, so I don't use them anymore.

My rulers are almost all the yellow/black omni grid so I use whatever size is best for what I'm doing. I also use a june tailor shape cut ruler and I have a truecut ruler plus a fiskars craft ruler w/ the blade attached and a regular 6 x 24 fiskars ruler. I use them all and so far no problems.

I use whatever ruler I have handy. I use mostly Omnigrid, but have used others (especially square rulers) when necessary.

Dumb question, but where do you put the fabric on the line? Right at the right edge, at the left edge or in the middle. Also some lines are thicker than others.

Doesn't matter as long as you're consistent.
Some people cut "wide", some cut "narrow".
This can also be affected by whether you are tall or short, stand to cut, or table height, did you know that?

Jan in VA