When you do those type of things you need a large work surface to hold all that fabric.Remember "measure twice,cut once".
Kathi

Are you remembering to add inches for the hems on both sides of the blinds? Depending on how deep of a hem you're making, you need to add x number of inches. Say for an inch wide hem, you'd add two inches, PLUS at least anothr half. That would allow 1/4" turned under, and an inch turned for the hem on each side. '

Even as long as I've been sewing, and cutting boards, sheetrock, etc. for projects, I can still mismeasure, even doing the twice, once rule.

I don't know why you'd be running long, too narrow could be b/c of not accounting for side seams as marg said. I would say if you were too short, it was b/c you weren't allowing for all the horizontal seams for the dowels in romans.

Next time you're making inside-mount romans, why don't you purposely cut a little wider and longer than what you figure even including seams/hems, finish the top and one side, then hang it and *mark* the actual fabric to the width & length you want (allowing for seams), then finish off that last side and bottom?

Any good carpenter will tell you it's better to mark than measure if you can.

If your house is anything like mine, part of the problem could be the house. My DH & I have laid wood flooring and tile and recently installed a bathroom vanity, and nothing in our house is square, flat or level.

Donna

Oh, definitely, if making inside-mount romans, measure at least 3 points across and 3 points down the window - take the smallest of each measurement. That's what they tell you to do for made to measure from JCP, etc. I ordered inside mount romans for my (then) 1-yr old house and even the same window size (according to Andersen) were slightly different, and they were also installed a tiny bit skewed.

Here is a link that might be useful: JCP measuring for roman shades