I totally agree with those recommending the use of sandpaper. Keeps the fabric from moving which seems to be your problem. I too always use a mechanical pencil. Works for me.

Beware of ballpoints - mentioned by another poster earlier. I had been using them without an issue for HST and then grabbed one from my local bank and discovered to my horror that the bit of ink at the cut line of the HST bled right onto the front of the HST fabric when it was washed. Lavender and cream tone-on-tone. Awful, and couldn't get it out.

I know what you mean about the fabric pulling, because that happened to me with the .008 permanent micro-marker I used - it scraped on the fabric because it was too fine a point on the pen.

I use colored pencils in a near-match to the front of the fabric now, or Frixion. they ride smoother.

FYI I put samples of Frixion-erased fabric in the freezer and in the fridge, and the lines never came back. It would have been red on solid yellow and there wasn't a trace of it.

Helen, what you might want to try, make sure you are holding down the ruler, then from the middle mark up (away from you) then mark down, (toward you but with a light hand. Try and see if that helps. The sandpaper helps too.

I also agree with Jan that starting in the middle. If you are worried about the 1/4 there is tape that is 1/4, but what I have done is mark the throat plate with BLUE painting tape so it keeps the fabric in the right position:D

I use the #2 pencil to mark with no problems, dark fabric I have a white chalk pencil that I use.

To answer your question: Yes, the frixion gel pens do iron away, I love using them for FMQ because you can mark it clearly to make a perfect design. But I agree with the others if you are going to cut on that line it might show through to the other side if the fabric is very light only, in that case...just snip off he edges carefully after you sew.

Make yourself a manila folder with a piece of fine sandpaper, just glue the sandpaper down onto the folder and when not in use the folder will protect the sandpaper. This, to me, is the best way to mark lines for half-square and quarter square triangles, as the sandpaper stabilizes the fabric for easier marking with a mechanical pencil. If you have a 1/4" foot on your sewing machine, use that, put the edge of the foot just over the line to sew a scant 1/4" accurately. hope this helps.

I use Jenny D's method, fold, press and then using 1/4" food sew on either side. No marking required and easy as can be.

If you are having difficulty getting accuracy using the drawn line technique, you might want to try ironing your HST's, in half, instead. It might help alleviate inaccuracies from the gap of the ruler to the pencil/pen, and the width of the pen line itself, and then where exactly to sew.

Just a thought.

Thanks so much to everyone for their great ideas and help. I am going to re-do my sandpaper, use the gel pens when they get here, fold in half and press like Jenny, mark from the middle up and middle down. Whew! Hope I remember all of this when it gets time to mark some. Also, I think cutting the squares a little bigger and trimming them down by using the 45 deg. line will help. Thanks so much for all the ideas. Y'all be good now, ya hear and stay warm! brrrrr! winter has arrived down south too!