string quuilt block question
 

I sewed some string blocks on 12- inch muslin foundations.

I trimmed them to 12.5 inches.

Should I trim them to 12 inches?

And if I add a border, should I "line" it so it will have almost the same bulk/heftiness of the squarrs, or just use a single layer of fabric?

I would leave them at 12.5 unless you want smaller and no, I wouldn't line the border. I didn't line mine when I did one many years ago and it turned out fine.

I just read your post and thought the same - leave them at 12.5" - however I just re-read your post and then thought that the foundations were originally cut at 12 so that means that you have a 1/4" inch all the way around the foundation with nothing on it if I am understanding correctly what you have said?

If that is the case then I would trim them to the same size. ie 12".

As for the border I would just make that without any foundation.

I look forward to seeing the end result.

You understtod correctly. I sewed them many years ago - and got stuck with indecion at that point.

busy fingers - it's the opposite, she has 1/4" all around the foundation with the strings on it, and there is no foundation under the edges of the blocks.

Are the seams of the string fabrics sewn all the way to the edges of the 12.5" line? If not, you will may have open seams if you leave these at 12.5" unfinished. As far as adding a foundation under the sashing, I don't think it would be necessary. When a quilt is finished, there are always some areas (seams, applique, etc.) where there are more layers of fabric than in other areas.

I would think that you would leave the extra half-inch, if you can. It would make the seams less thick. I'm not an expert, however.

I would definitely line the borders so all will be the same thickness. Also if you are putting sashing in I would line that as well. As to leaving edges without foundation. I would trim to 12" so again, all would be the same, otherwise there might be some of the seams bulkier than others due to catching some of the foundation in the seam and some areas just the string. Leaving some areas without foundation can cause difficulty in quiting, both home machine as well as long arm.
I have taught string quilting and always recommending this way to make the entire top consistent.

I would trim to 12 inches. No need to line the sashing. I have used interfacing on t-shirts but not the sashing when making a t-shirt quilt. Differences in the thickness did not matter. When you do appliqué, you will have a difference in thickness there too and that is not an issue. This is just what I would do. A lot of people will have a different opinion. I don't think it will matter much either way. Post pix when you are done!!