Is there a formula to figure out how much thread to use on a project?

[Sjm1027]

Is there a formula to figure out how much thread to use on a project? If I have a rectangle I need to sew together and I add all the sides lengths up to total 28 inches how long of a piece of thread should I use?

Thanks,

-S

[Brandon]

I normally do saddle stitch and I used four times the length so as not to struggle towards the end.

Pull the thread around the perimeter of the project, fold/double it ( thread ) once and from that length fold it again, that should be about four times the wanted length.

B.

[RandyScott]

The topic of thread length has come up before and will again. I, also a noobe or beginner, just could not accept 'it depends' till I work out the ratio of thread seam length to thread length, sewed my first seam and promptly forgot the ratio. It really does 'depend' on many variables such as weight of leather, total pieces to be joined, stitches per inch, etc.. To determine thread length one adds up the various distances or thickness of each leg of each stitch. For example, using 2 pieces of 8 ounce for a total thickness of 16 ounces or 16/64 = 1/4" thick, 4 stitches per inch for 1 inch and using a saddle stitch I estimate about 4" to the linear seam inch. Note that the thread requirement consists of a fixed and a variable measure. The fixed is the seam length. The variable is the stitches per inch. 8 SPI will require more thread than 4. And don't forget, as I did, that you need extra thread so that when reaching the end of the seam you have sufficient thread to manouver thread and needle. It really is frustrating to have 4 stitches left and not enough thread because I forgot to add an extra 12" per side for handling.

Or, use the span method. A span being the width of your outspread arms - roughly 5 to 6 feet for most folks. This amount of thread allows one to sew with two needles and an awl and never drop the needles nor awl, allows one to pull and seat the thread without having to drop and pick up anything. IF one runs out of thread, tie it off and start with a fresh thread. The Al Lohman book The Art of Handsewing Leather and available at a reasonable price from any leather supplier details the technique of this method, tieing off and many others.

Those who use 'rules of thumb' have developed those rules through experience and repitition, i.e., they use the same stitch method, weight of leather, piece count, etc., over and over and develop their unique and individual 'rule of thumb'.

And finally, initially you gave a seam length of 28 inches. Using, as an example, a 4 to 1 ratio: 4 x 28 = 112" + 12" + 12" + 6" = 142" or almost 12 feet of thread. The 12" is for working room when the seam is almosts finished and the 6" is for the amount of thread required to lock the thread to the needles.

Then again, I as a noobe or beginner, could be wrong. Regardless, I do wish you the best of luck on this journey.

Also, if this comes across as 'preachy', I sincerely apologize. My intent was to convey my journey through this topic.

Randy

[barra]

The length of thread should be no more than the double length of your arm so that you can pull up in one foul swoop so that you don't have to take a double grab to pull up one stitch, tho i guess that is only important if time is money. Don't get too fussed if you have to use more than one thread to complete a job.

Barra

Edited September 21, 2007 by barra

[Jordan]

I have had pretty good luck by measuring the length (or perimeter) then double it and add 1 more length for insurance, if that makes sense, it does get unwieldly on larger stuff but if you sew fast it becomes managable

Edited October 6, 2007 by Jordan