Wednesday, May 14, 2008

I don't have enough yarn

(OK, in this case, I really don't!)

Previously posted on Ravelry, reposted here for posterity:

I just figured out I don’t have enough yarn for a project and thought I’d share my methods. Feedback welcome. (I’m sad that I can’t make it, but happy I figured it out now rather than partway up the front and having to quit _then_…!)

I had several skeins of Worsted Border Leicester/Corriedale in “Black Orchid” from Rabbitworks Fibre Studio. She had also thrown in a swatch/scarf she’d started in the wool, so my first order of business was to frog that, skein it, wash it, and hang it to get rid of the wigglies. Once I did that, I counted the strands at one end of each skein to get the yardage (my niddy-noddy measures 1-yd skeins).

So now, I had 84 + 76 (the two frogged skeins) + 60 + 130 + 130 (the labeled skeins) = 490 yards.

I grabbed the smallest skein, cast on about 5” wide in stitches, and began knitting for a swatch. A little more than halfway through the ball, I realized that it would be more useful to knit up the entire thing and measure it for my intended project, Boogie Vest. It knit up quickly on 8s, so I kept going, and the end product measured 8x12”.

Since we know 60 yards made 8x12” of fabric, we can extrapolate from that to estimate yardage needed for a vest.

I used the measurements from Ann Budd’s Knitter’s Handy Book of Patterns to estimate fabric needed. I drew a rectangle for the lower half of the vest, and then modified rectangles for the upper part (narrower width on the edges to show the armholes, and a v-neck in the middle). For my size, I would have

lower rectangle 22 x 14 x 1 piece = 308 square inches (sq in)
upper rectangle, the square outer part 4.75 x 10 x 2 of these = 95 sq in
V-neck part consists of two triangles, so we can do width x height once
to get the area for both: 7 x 10 = 70 sq in
Total: 473 sq in for front

Roughly, one big rectangle
22 x 24 x 1 piece = 528 sq in

Grand Total: 1001 sq in needed.

My knitted piece is 96 sq in from a 60-yd skein, yielding 1.6 sq in per yard (96/60 = 1.6 sq in).

So my 490 yards at 1.6 sq in per yard would yield 784 sq in, more than 200 sq in less than I need.

Of course, this is all estimated, but a back-of-the-envelope calculation can certainly give you the answer you need (but don’t want): don’t even start it.


Dharma said...

I'm sorry honey. But yes it is better to know now.

Anonymous said...

You are brilliant! It is, indeed, much better to figure this out than to have to abandon the project partway through. Sorry you don't have enough. Do you have another yarn you can use? samm