Considerations When Making Yarn Substitutions

Qualities of the Original Yarn:

--Gauge and Yarn weight
Usually, the gauge can be matched by using a yarn from the same category on the CYCA “Standard Yarn Weight System.”  Yarn weight refers to the thickness of a yarn. The CYCA yarn standards categorize yarn based on wpi or wraps per inch and ypp or yards per pound.

For worsted weight yarn(#4):  Using the yarn from the pattern, determine the number of yards per 50 grams; figure 15%.  Look at the yarn you want to substitute and figure the number of yards per 50 grams.  If this number is within 15% higher or lower than the original yarn, it is probably a good match.
For fingering ( #1), sock (#2) and  dk weight (#3) figure 20%. For bulky (#5) and super bulky (#6), figure 10%.

To determine the approximate gauge a yarn will knit when two strands are held together (doubled):  multiply the stitches per 4 inches listed on the ball band by .73 (or 73 %).  Remember you will need to double the amount of yardage that you buy.

--Fiber
Fiber content will influence how a yarn looks when knitted. Substituting a yarn with similar fiber content and structure will help obtain a fabric similar to the original. Animal, plant and synthetic fibers all have unique characteristics. All yarns will have specific qualities depending on their source.
--Ply
Compare the ply of the substitute yarn and the original yarn. Ply affects a yarn’s balance. Single ply and various multiple ply yarns will all work up differently. Even the direction of the ply (Z or S) will affect a fabric’s look.
--Texture
Determine if the item being made needs a certain texture for the yarn. Smooth yarns will highlight stitch work better.  Other textures include slubby, boucle, haloed eyelash, and thick and thin yarn.
--Drape
Fiber, ply, texture and gauge will all affect the eventual drape of the fabric. Drape is a description of the firmness of the knitted fabric. Decide on how flexible or stiff the finished fabric should be and choose a yarn with a fiber, texture and ply worked at a set gauge that creates this drape.

Other Considerations:
Use- Stranding, steeking, felting, lace, cabling.....
Color- Check that colors will work with stitch pattern and/ or written pattern. Check for bleeding.
The Recipient- Consider preferences, allergies, cost, and care.

Work a Swatch
Make a swatch that is at least four inches by four inches. Include stitch or color patterns from the pattern. While working the swatch look for any potential problems and see how the yarn feels to your hand. Check the gauge.  Block the swatch. Check the gauge again. Blocking will also give you an idea of how the yarn launders.   See the post on how to measure gauge.

Buy the Right Amount:
Using the original, yarn multiply the yards per ball by the number of balls needed for the pattern.  This gives the total yardage necessary.  Take this number and divide it by the yardage per ball of the new yarn to find the number of balls needed.  Consider getting extra yardage, you never know if you will need it.

# of yds on original ball of yarn  x  # of balls needed for size on pattern ÷ # yds on substitute ball of yarn = # of balls needed of substitute yarn.