From: alg@cs.cornell.edu (Anne Louise Gockel)
Subject: Quilting: Curved Strip Piecing
Organization: Cornell University, Ithaca NY
Date: Sun, 26 Jul 1992 13:24:35 GMT

A few weeks ago I experimented with curved strip piecing.  This is a technique
described in the book _Curved Strip-Piecing_ by Marilyn Stothers, copyright
1988.  ISBN 0-88925-899-6.  Published by PH PRess , c/o Marilyn Stothers, 85
Agassiz Drive, Winnipeg Manitoba, Canada R3T 2K9. (was $18.95 + 2.50 p&h
Canadian dollars).

I've had this book for several years and finally decided to try the techniques
with an exchange block.  I made a 12"x12" rail fence block using the C.S.P.
methods.

Curved Strip Piecing is similar to strip piecing except rather than straight
seams, the strips are sewn together with gentle, random curves.  Stothers book
includes
	-) explanation how to sew the strips
	-) two methods of cutting the strips
	-) many pictures and project ideas
I'll try to summarize some of her ideas, but if you're really interested in
trying this, get a copy of her book for more details.

To cut two strips to be pieced together, lay one fabric on top of the other.
Both pieces should be folded on the length-wise fold (e.g. 45" folded in half
to 22") and the folds should be exactly lined up.  The two pieces of fabric
are cut together so that the curves of the one are exactly the inverse of the
curves of the other.  Note:
	-) you *cannot* make any corrections!  The curves must be exact 
	inverses.  You have one chance to make these gentle, random curves;
	don't try to backtrack!
	-) Stothers recommends using scissors rather than a rotary cutter so 
	you maintain more control
	-) You will be making a series of (random) gentle curves and valleys.  
	I found that the tightest hills were:
		-) 1/2" from top of the peak to bottom of the valley
		-) 2&1/2" from top of one hill to top of the next hill
	Hills that were "tighter" than this would be too difficult to sew; this
	is the "tighest" that is feasible.
	For a large project, hills that are very easy to sew are about:
		-) 1/2" from top of the peak to bottom of the valley
		-) 6" from top of one hill to top of the next hill
	These are very easy to sew.
	-) You must use gentle *curves*.  You cannot use sharp turns or angles.
	-) Start at the center fold; cut straight for the first 1/2-1". Start
	the cut perpendicular to the center fold and then start the curves.  If
	you cut at an angle on the fold you'll get a V instead of a curve 
	there!
	-) You will be wasting 1/2"-1&1/2" for each strip for the area where 
	you cut the curves.  

Stothers outlines two ways of lining up your fabric: 
	a) if you want a specific series of colors you will be cutting each 
	set of strips randomly.  There's a fair amount of waste with this 
	method
	b) if you can use a random series of colors you can cut everything at
	the same time and there is very little waste.  Since you're cutting 
	several fabrics at one, you just have to match some fabric in the first
	pile with some fabric in the second pile for each seam.
See her book for more details on the layout of these two methods.

To sew the strips, first pin them carefully.  Stothers warns that you must pin
them and I agree.  Lay the two pieces together right sides together and match
them at the center fold.  You will note that where one piece has a valley, the
bother piece has a hill and vica versa.  Align the two fabrics so that the
hills and valleys are matched up.  Each place where the two fabrics cross each
other, place a pin.  For example, as the bottom fabric is heading up to the
top of a hill and the bottom fabric is heading down to the bottom of a valley,
the two fabrics will cross each other.  Place a pin at that point.  Pin each
crossing.  (The book has some illustrations showing how to pin and sew the
pieces.)

When you sew the fabrics together, use a 1/4" seam allowance.  However the
seam allowance is not as strict as in regular quilting; you can allow the SA
to vary if you need to while easing in some of the curves.  The pins will keep
the two fabrics aligned.  I find it best to remove pins about 1" before the
sewing machine needle.  You will be gentley stretching and easing each curve
to fit them together.  After you've done a bit you'll find it fairly
straightforward.

When you're done sewing the seams, press them.  I first press them closed and
then press to one side from the back.  It doesn't matter which side, the
fabric may tend to lie to one side or another.  Then press the strips
aggressively from the front to make them lie flat.

I think that the c.s.p. quilt top should be heavily quilted.  The strips look
*great* shortly after pressing, but soon relax and look less neat.  I think
that a fair amount of quilting would help keep them looking neat.  This may
mean that c.s.p. is good for quilt-as-you-go since you would be able to iron
small areas and quilt them quickly.

This technique is *slow*.  I found that, even after practicing for a while, it
spent about 45 minutes cutting, sewing and ironing one seam in 45" material.
So making three strips with two seams between them took about 1.5 hours.  I
don't think it gets alot faster than this!

Curved Strip Piecing looks very unique and interesting in most designs in
which you would use regular strip piecing.  The overall affect is somewhat
random and much softer than traditional curved piecing.  In some of Stother's
work (24+/- color pictures are in the book, most are using C.S.P!) the strip
piecing looks like the colors are melting. In another piece that I think
represents the sun the C.S.P. gives the impresion of the heat waves that you
see rising from a hot sidewalk.  In another piece, the C.S.P. seems to
represent the ripples of water.  Most of Stother's work has C.S.P. section
that are sew together using traditional straight seams.  The straight seams
provide the contrast neccessary to set off the C.S.P. sections.

C.S.P. can also be used in any traditional block where you might use strip
piecing.  Generally you'll want to be sure that pieces of fabric are 4" or
longer so you have a chance to see the curves.  Note also that you will NOT be
able to make points meet in any meaningful sense!  You may be combining C.S.P.
with straight seams in the construction (see the samples in Stother's book).
Any seam that you plan to sew as a C.S.P. seam needs to have 1/2" or more of
extra material on each side to allow it to be re-cut for the curves for the
C.S.P. seam!

C.S.P. probably shouldn't be used for Seminole Piecing since the S.P. pieces
are a bit too small.  If a section of C.S.P. is less than about 3" it may look
like sloppy work rather than a unique technique.

I would love to see the C.S.P. techniques combined with Joen Wolfram's
abstract image quilts (see her _Landscapes and Illusions_) for a wonderful
abstract image of mountains and water.  The biggest drawback is that this
would be a very very slow quilt to piece!

All in all, I was very happy with my C.S.P. samples.  For quite a while, I've
had plans for a quilt that uses C.S.P. with some hand dyed gradiated materials
for a lap quilt.  I think that project will turn out very well if I can find
the time to make it!

					-Anne
Anne Louise Gockel			Cornell Computer Science
Internet: alg@cs.cornell.edu		UUCP: cornell!alg