My Free Patterns

I am still sorting out the blog entries for my free patterns, so there willl still be patterns that are not accessible. My apologies.

Wednesday, 9 March 2011

How to estimate the amount of thread required for a project

I often receive e-mails from tatters asking how to determine how much thread is required for a tatting project.  Most of the time I would reply direct to the sender, but I think it would be best if I put this up as a post so that more people will have the information. My method requires very basic arithmetic so it should not put off anyone who is mathematically-challenged, :). This post may sound a bit academic in some parts, but what I am sharing is as how I do it. However, there is still some element of guess-timation in the calculation.

There are a few things to consider,
  • the size of thread that you are using;
  • the number of repeats in the pattern;
  • if there are lots of decorative picots and the size of the picots.
  • the length of the chains, and
  • the size of the rings.
Before starting my project, I pick the thread that I want to use and tat 10 ds with it. Then I undo the all 10 ds and measure the length of thread used to make that 10 ds, for example 5cm.

To estimate the amount of thread required, I first count the number of stitches in the rings to make one repeat of the motif.  Let us suppose that the total number of stitches is 280. Then, I count the number of rings in that one repeat.  Why number of rings? Because, the core thread of the rings can add up to the amount of thread needed.  Again, supposing that there are 10 rings in the one repeat.  Based on the size of the rings, let us assume that each ring will take up about 1cm of core thread.  Now look at the chains.  Chains uses the shuttle thread as the core thread.  Longer chain uses up more thread, so we need to give some allowance for chains as well.

Let us see what we have so far.

For one repeat of the motif -
There are 280 double-stitches. 
10 stitches uses up 5 cm of thread.
280 stitches will require (280 x 5) divide by 10, equals 140 cm of thread.
One ring takes up 1cm thread.
10 rings will use 10cm
We will assume that core thread for chains will take up about 8cm.
From these figures, we can add up the length of thread required for one repeat as,
140cm (ds) + 10cm (rings) +8cm (chains) = 158cm
If there are long picots or many decorative picots in one repeat, you'll need to take them into account too, say 20cm.
Adding the amount for the picots, the length for one repeat now becomes 158cm + 20cm = 178cm.

Now count the number of repeats that you will need.  Snowflakes will take six repeats but edgings will require additional calculation, which I will address later.

Assuming that the motif is a snowflake, then the total amount of thread required will be,
178cm x 6 repeats = 1,068cm or 10.68 metres, rounded up to 11 metres

Chains will be using up the ball thread to make the double-stitches, so we need to calculate this amount to get the total amount of thread to complete the project.

As with the rings, calculate the total number of double stitches in the chains, let's say 150 stitches per one repeat. Using the same measure of 5cm taking up 10 stitches, 150 stitches will take up
(150 stitches x 5cm ) divide by 10 stitches = 75cm.
Multiply that by the number of repeat (six in this example), 75cm x 6 repeat = 450cm or 4.5metres

Add the total for the rings and the total for the chains to get the total amount of thread to complete the whole project, 11 metres (rings) + 4.5 metres (chains) = 15.5 metres.

If you are making an edging with several repeats, it will be useful to determine how many repeats in total will be needed.  So after tatting the first repeat, I would measure the width of the tatting, lets say each repeat is 5cm wide.  Then I measure the outer edge of the piece where I will be attaching the edging to, say 120cm.
The number of repeats that I will need to complete the edging will be 120cm/5cm = 24 repeats.
The amount of thread that I may need to complete the project will be, 15.5metres X 24 repeats = 372metres.

What we have done so far is to determine the amount required for the shuttle thread for a shuttle-and-ball pattern.  Usually, I will add 50cm more, and make the first motif. At the end of it I will be able to find out if I am short of thread, just enough or extra. I make adjustments for the next motif for the shortage or excess thread.

Calculating for a two-shuttle pattern is a bit more involved because you need to know which part of the pattern uses thread from shuttle 1 and which part uses thread from shuttle 2.  Once this is determined, the same method can be used to calculate the amount of thread for each shuttle.  Having said that, for big projects I would just load two full shuttles at the beginning because I know that either shuttle, or both, will run out of thread before I even finish my project.

I am sorry if this appears all too complicated to some, but this is the method that I have been using and I found it not far off. But, I have an advantage in that I like maths so this is not really a problem for me, he he ..... and I don't know any other way that is close enough.

After that heavy reading, here is a picture of a pair of earrings that I made, while you catch your breath and maybe relax your mind a bit.



11 comments:

  1. Thank you for the information on how to figure the amount of thread needed. I have been just filling my shuttles full of thread only to wind up with a lot of extra thread on them after I finish a project. I don't like that as it waste thread. Now that won't happen anymore!
    The earrings are lovely!
    Blessings,
    Diane

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  2. Great Question! I always had this question.. but always forget to ask.
    THANK YOU! Thank you for addressing this!

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  3. Hola Jon, gracias por enseñarnos tu método, yo creo que no es complejo y sí muy útil. Yo desde hoy lo mvoy a emplear. Gracias y besos

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  4. You are correct, my head hurts...LOL I’m not a math person at all...so I ‘guesstimate’ and don’t waste too much thread; and have never run short in a pattern. Just lucky, I guess. That is a good method for those with a math mind.
    I just get a headache at the base of my skull...LOL
    I did manage “B’s” in Math during my teenage years....but it was really hard. We moved so often when I was in grammar school that I missed out on part of the math teaching. Used to move every 28 days! And moved 5 times my Freshman (9th grade) year of school...In spite of all that I graduated in the top 10% in a class of 800 graduates and made it through University....but I didn’t take many math classes. All Art, Education, and Animal science; oh...and graphic design (you do use math there).
    Your numbers brought all this to mind. LOL bj

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  5. Thank you so much! I'm not a math-whiz but I can follow directions. You have saved me (and I'm sure others) meters of wasted thread!

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  6. So far above my completely unmathematical head that I couldn't even see it! -but it's great,Jon, that you've worked out a formula for people who might be using HDT, for example, and don't want to waste any.
    I passed Higher Maths too, Bev, but that was nearly 50 years ago, and it didn't stick - I'm really good at mental arithmetic though! - lol
    My father was an engineer and I think he was utterly bemused by his daughter's lack of ability in something which he found so very easy.

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  7. I am sorry I gave you a headache, Bev, :)

    This is a guide, but something that works for me amd I hope it does for others as well. If you can figure out a less complicated or lengthy method, I am all ears, or rather all 'eyes'.

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  8. congrats, saw you were featured in
    Craft Gossip

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  9. Awesome! I also wanted to thank you for the lovely scraps from your original quilt. They're beautiful and I can't wait to make mine

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  10. Phew! Thank goodness for the pretty earrings at the end, lol!

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