Diagonal lines ?
 

How do you do them? Any help would be appreciated. BTW, I want to do a twin size quilt in diagonal lines. Am I nuts? It's ok, I can take it, lol.

I've used blue painter's tape and hand quilted along the edge in order to keep it straight. I know others will give you even better tips. Good luck and don't forget to post a picture when you are done! :)

someone here just posted a gorgeous photo of diagonal stitched lines. it was a close up of a block with red in it. applique i think. she used tape too.
you can also mark straight lines with a long ruler and a Hera marker. that is a plastic hand held tool that indents marks and you have nothing to wash out. even JoAnn's sells those.

When it comes to long diagonal lines I am a huge fan of painters tape, comes in different widths !

I use a disappearing ink marker to mark the lines then quilt on the lines. If you are hand quilting the lines might disappear before you finish your project so mark as you go. If you are machine quilting, the marks can last up to 48 hours but I have had them disappear within a few hours. It probably depends on the temperature and humidity. They wash out in the washer but don't iron over the marks before you wash them out or you might set the ink permenantly.

If machine quilting, I would heavily starch both the backing and the top before layering. This would help prevent the bias from stretching as you stitch. I like blue painter's tape for straight lines.

As I have not yet tackled the challenge of freemotion quilting I do diagonal lines on all mine with a walking foot. I have drawn with (supposedly) washable pencil, eyeballed it from corner to corner on square blocks, used painters tape, and most recently tried the hera tool. The hera is my favorite! I used it after I had sandwiched my quilt and basted with safety pins. It worked really well with my hars wood floors. I will try again - this time without the sandwich and hope for the same results. You'll be fine! Just baste well.

You know, I recently did cross-hatch quilting lines on a wall hanging, and because I didn't have any painter's tape handy, I used disappearing ink to draw a line from one corner to the other (diagonally across my quilt, so that I ended up with a big X in the area where I wanted to do the cross-hatch quilting), sewed along those lines (very quickly, before the ink disappeared ;)), and then used the edge guide that came with my machine (a metal piece that extends out from the foot of my machine, and can be adjusted so that it follows the edge of the fabric when sewing a wide hem, etc.) to follow the lines I had already stitched, at 1 1/2" intervals (I also switched directions each time I sewed a line, so that my fabric didn't shift too much one direction or the other). It worked pretty slick, and saved me from having to run to the store for painter's tape :thumbup:

I have used diagonals on just about all the baby quilts I make. I use my Omnigrid yardstick to make the lines 1 1/2 inches wide. My favorite marker is the blue washable marker. I always make test marks on all the fabrics used in the quilt before I start piecing. Then when I am ready to mark, I get the test marks wet with cold water to double check they will come out. I have ironed over them and the marks still come out, but I wouldn't recommend this as the directions say not to. Anyway, I like to use a converging chevron pattern, so that begining X gets filled in on all sides with diagonals. I use my walking foot to follow the marked lines. After it is bound, I agitate the quilt in cold water, spin that out, then wash with warm. Into the dryer and it is done.