Marking an antique quilt
 

I'm currently hand quilting my great-grandmother's Dresden Plate quilt. The blocks sat in a trunk in the attic for decades, and it just seemed right to put them together and finish it! I typically use a hera to mark for hand quilting, but with a Dresden Plate the open areas are quite large and I think it would be very fiddly to keep outlining the different elements of the design with a hera. I'm hesitant to use anything that has any chance of marking permanently or re-appearing. Due to its age and fragility this quilt will not be washed, so anything that requires laundering to remove it isn't an option. Ideas?

I really love the General's Charcoal White pencils. But they don't mark very well on a white background. Don't know what color fabric you're quilting on. But they sharpen very well, write very well, and come off very well -- much better than chalk.

White chalk on dark areas, purple air soluble marker on white areas? These, along with the blue water soluble marker, are what Jamie Waller recommends.

It might depend on how "fiddly" your quilt design is but if you are using enough straight lines, can you put the stencil where you want to mark, placing straight pins upright where you'd usually do marking? Then stitch from one pin to the next, removing them as you go.
As to washing, If those sat for a long time, the finished quilt may benefit from a gentle wash. I don't know that I'd put it in the machine but perhaps in the bath tub and squishing water through it and then put it through a spin cycle in the washer to get the rest of the water out. I recently finished and hand quilted a very old top. It did fine and the laundry brightened it up that it looks--and smells--"new" again.
If these were blocks and you've handled them putting them together, you know the integrity of the fabric at this time. If they've done well with being constructed into a top, they probably will do ok in getting a bath. Just be gentle.

If you're planning lots of straight line quilting then 1/4 inch masking tape could work well.

I sometimes use my Hera markers. plastic markers you use to make indentations in the fabric for quilting lines. Just a thought.

You have a treasure!!!!!!!!
Are you sure you can't wash it? I have several antique quilts that I've washed and they didn't get damaged at all. I soaked them and then spread them out to dry.
But to answer your question I would use chalk.
Please show us when you are finished!

If you are wanting to do some simple stencil marking, trace it onto freezer paper and cut it out carefully, then iron this onto the top, and quilt around it, and then peel the paper off. Be careful your iron is not too hot; if your batting has poly in it, maybe try a sample sandwich first.

I do indeed have a treasure! My great-grandmother died in 1942, so this quilt top is over 80 years old. I'm afraid to wash it, as some of the stitching looks fragile. Also, some of the fabrics are red, and I would be horrified if they bled when washed. Based on y'all's advice I've just ordered some General's white charcoal pencils, hoping that perhaps they will show even the slightest line, as the background fabric is an off-white muslin. In case the charcoal pencil doesn't do the trick, I have also ordered a fine line air erasable marker. I read that one ingredient of the air erasable marker is an acid, and I'm a little concerned about the long-term effect of this on antique fabric. At any rate, I'm considering all the possibilities for marking. I appreciate everyone's help and advice. Thank you so much! Oh -- an interesting side note: I ordered a 30's repro fabric for the backing. When it came, I discovered that it matched one of the original 30's fabrics in the top, almost exactly! How's THAT for a happy accident!

I would use a mechanical pencil to mark the quilt. No ink or dye that could stain it. Mark lightly & it will come out.