It's great when you can cut 76" of bias strips for your fabric. (This is the longest length on a 54" bolt of fabric if you cut at a 45 degree angle.)
But sometimes I need to cut on the bias and I also need to conserve as much of the fabric as possible because I just don't have much excess fabric to waste.
This is how I figure out exactly how much fabric I need for my welt cord:
Example:
I have a sofa that needs 950" of welt cord. I am going to cut the fabric on the bias.
My fabric is 54" wide.
My welt cord strips of fabric will be 1 1/2" wide.
54" divided into 950" = 17.6
I need 17.6 strips of fabric. I round up to 18 strips of fabric.
18 x 1 1/2" = 27".
If I cut 27" of my 54" wide fabric, and cut this on the bias, I will have my 950" of fabric for my welt cord.
gene
I userstand fir a full strips at a 45• you need 950" and get 27" out of it
But you will have 2 triangle pieces one at each end do you not you this material to make shorter strips ?
I no any strip shorted then say 30" would be silly but it would use less in a pinch.
I don't use fabric much o. Boat unless it's inside and not much inside work is done I Hesse it not that important to most by the tine the insides bad they get a new boat And the guy buying a older boat don't care so much
Gene,
I just order enough fabric to accommodate bias welt. 1 1/2 extra for a chair and 3 for a sofa.
Those triangle pieces left at the end will usually do for something, such as a skirt flap, or a front arm panel.
Gene: Based on those figures, how long is your shortest strip?
In this example I rounded up to a full 18 strips. This gives me extra inches. I do lose a few inches on each strip when I sew them together on the diagonal. I also only go down to about a 15" strip. What's left is the triangle you are talking about.
The thing to remember is the stretch on the bias. I have never gone short on welt cord with this method.
And, I certainly prefer to add yardage to the total to allow for the welt cord.
gene
Gene, I have always found that since it stretches on the bias.. there is ALWYAS way more than you can mathematically account for.
Nice formula. :-)