I would give the lady the dimensions of the quilt & border and let her get what she thinks she needs. It takes the burden off of you and puts it on her.

John Flynn has the system for saving fabric by cutting the piece diagonally. You have to calculate how much fabric by using a formula. What I did was subtact the usable width of fabric from the width of the quilt. Example (64 + 4)-40=28) 4" inches alows the overhang for the backing, then I took a piec of fabric (any fabric) and marked a diagonal line, measure from inside the selvege to the line and move down until you have a measurement of 24" (from the diagonal line to selvege). That measurement you add to the length of your quilt 68+ (measurement) and that is the amount of fabric you need to back the quilt. This allows 2" overhang around each side. I always buy at buy about 1/3 of a yard more for fudge factor and the extra overhang of the back. Now at some point (if the quilt is too wide) it will not save you fabric and you have to buy 2 times the length or what ever.

Since these kids are just learning, I think the best thing is to go with twice the length and be done with it.

If this woman's child were in public school, what she is spending on fabric for this project would be a drop in the bucket compared with the supplies kids need there, not to mentionthat public school teachers don't have time to provide any neat activities like making a quilt. Shame on her! froggyintexas

Thank you again to all the great responses. I do want to say that it shouldnt' be a money issue, I included in my syllabus taht if money was ever an issue to email me privately and we would come up with fabric for anyone that truly wanted to learn to quilt. I think maybe she was just in a bit of shock at everything and having others whisper in your ear can be swaying. I am just glad that my math was right. I hope everyone had a fantastic weekend.

Tammy

Jimminy crickets. I taught a beginners sewing class for our local homeschool group. We sewed together christmas stockings. I never had any complain about amounts of fabric or trims. Even had some swapping so they could make different looking stockings for grandparents. If she had an issue with the quantity I would have shared a coupon so that money wouldn't be the issue. But graph paper is always a great solution.

I think you would be closer at 4 yards! 3-1/4 yards is really cutting it close. You are never wasteful with fabric. Leftovers go into another quilt. You never waste anything. That lady is being picky.

Maybe the mom was looking at "backing fabric" that is 90 to 108 inches wide. Explain the difference to her. If she wants to purchase the more expensive "backing fabric" she would need a LOT less, but it would be cheaper to buy regular fabric and more of it.

That certainly is not enough for a king.I make king all the time and you need 10 yards of 42 in. fabric for a king back.You also need to tell the lady that the quilting pulls in the fabric in the back so depending on the loft of the batting you need the back to be at least 6 in. longer and wider than the front.This is a thing the inexperienced clerk did not know.If the loft of the batting is deep the backing must be bigger than the 6 in.

Used to teach quilting/patchwork to many ages. All suggestions excellent-but a few more ? How old is this student? Is this a first project? How are you going "quilt" or secure layers together? (sheets are hard to quilt especially by hand) If you are using "tying" then new sheets work. One thing we used to do is ask for fabric for top so student can start sewing and " contract " for backing from parent when top is complete. You might also provide list of reasonably priced sources. In ou area that would be Walmart, and Joannes during a sale or even "goodwill" if they understand what kind of fabric you need for project. if you get stuck start asking around -many people buy fabric and never use it.They are only too willing to donate and support a child. Another place to appeal to is your local quilt group and their friends . A quick thank you note delights many people and builds community for kids. It's also possible your local quilt shop has a "dog" bolt they will donate or sell for very little-one class of teenagers I worked with took donated bolt and everyone of them used it in either the front or on the back. One person's ugly became part of a very successful class.
In this economy $35 or $40 is a lot of money for people to invest especially if they don't sew themselves

Tammy, did this mom question every teacher in her or her child's past? Does she or her friend at JoAnn's teach quilting? Cutting material or birthing a child does NOT make her a professional. Is this woman normally confrontational? Some people are, unfortunately.

If she'd prefer to teach quilting 101, tell her to have at it. Or instead, she can choose to remove her child from your co-op and supplement the learning with something else...maybe a class at JoAnn's at her expense.

Maybe I'm just off base and maybe she can't afford the material. She could always go to Goodwill and purchase bed linens and cut them to the desired size! From what I hear on this site, there's a lot of bargains with the material at local donation stores or garage sales!

Tell the mom that it takes 9 yards to do a king size quilt.... King size is 104 x 104...at least... 3 yards is 108"...and that's the width. I sew 2 -1/2 of the three yard lengths together...the other 22 x 3 yard piece is the binding...and there is a little left over. It's the only way to not have to piece a ton of little bits together to make a back.

Find a pattern that is about the size your quilt will end up...see what it says to use for backing...let the parents know what the amount is.

Marge

Don't forget that the student needs some of the backin fabric for borders......this fact appears to be ignored in the comments. Borders needed - backing can be changed.

I have not read threw all the post, but maybe the mother can't afford that amount, so instead of saying she needs help with costs, she does it this way, so it would be less embarresing for her.
Just a thought.
GOD bless.

I know you hate to disappoint the child because of the mom, but sometimes you need to. This is a life lesson for the parent.

I commend you for thinking of the money issue up front. But, even with that, many people have a hard time being honest about their money situation and react the way she did. If this is a possiblity, suggesting alternative backings such as sheets(use low thread count sheets) could ease her fears of too much money being spent.
It's wonderful that you are teaching the young ones to quilt. :-)

We will be waiting to know how you handled the situation

I met her today and after hearing the explaination for cutting it in half to make it wider not long she understood why that amount was needed. I also brought a king size quilt with me so that I could show her exactly how big that is.

I did explain to her that next time she had questions she should talk to me first rather than get opinons from others that might not have the same vision as I do because assumptions are the mother of all things bad.

Thank you all so much for keeping my backbone strong, its good to know my friends have my back. :)

I will post pictures of their finished masterpieces some time in Dec. I really am enjoying teaching the girls, they get so excited to see their accomplisments.

Hi, I'm cutting this Mom a break thinking perhaps she just can't afford it. I would ask her to get the fabric for the border and suggest she get the backing fabric at a later date. I would suggest using a solid as that can easily be purchased at a later date. Also suggest pieced border using some of the leftover pieces from the top or cotton fabric pieces from outgrown clothing would work if it all cotton. This would not only look really good but also cut down on the cost. I would present these as options in a kind way. The most important thing is the child has some fun with this and he or she probably already heard it's wasting money. Making quilts can be done spending a whole lot on fabric and also done using scraps.
However, your calculations do sound pretty accurate.