Wait, another initialism? Yep!
We’ve already talked about EPI (used for warp spacing), and briefly mentioned WPI (used to determine yarn sizing), so now it’s time to talk about PPI! This isn’t the first time I’ve talked about PPI. I mentioned PPI in my post about planning your weaving. But it’s time to really dig in and talk about why it’s important and what it really means for your woven artwork.
I talk more about WPI in my Weaving Planning e-book! Click the image below to learn more!
What is PPI?
PPI stands for Picks Per Inch and is a measurement of the weft in your weaving. More specifically, how many weft yarns can be found in a single inch of a weaving.
Ok, great, but, what is a pick?
A pick is when your weft yarn goes across your weaving in one direction, but not back. Each time your weft passes through your shed is one pick. This can also be called a half pass or a shot.
This is where the technique pick-and-pick gets it’s name. Pick-and-pick is weaving technique that creates vertical stripes through the use of 2 different colors that each only pass through one shed. So you will weave one pick of color A and then one pick of color B. Repeat. With this weaving pattern color A will only ever weave on top of warps 1 & 3, and color B will only ever weave on top of warps 2 & 4 which is what creates the vertical lines.
Why is PPI important?
One of the most important reasons to figure out your PPI is when you are planning your weaving and trying to figure out how much yarn you need! Knowing how many weft yarns you have per inch of your weaving will allow you to more accurately measure how much yarn you need total. Once you find out your PPI you can plug it into a weaving calculator like the one I link to in my weaving planning post, or do the math yourself! ( I also walk you through that in the same post or you can get my e-book and get an exclusive weaving planning worksheet)
Here’s a really simple tip for PPI for a balanced weave: it’s the same as the EPI!
Since a balanced weave shows the same amount of warp as it does weft, the Picks Per Inch and the Ends Per Inch should be the same!
What if you’re not weaving balanced weave?
Well, then it’s time for you to weave up a sample! If you already know what EPI you plan to use for your weaving then you can use a frame loom to set up your sample. You could also use some leftover warp on a floor loom if you have one that is already set up for the correct EPI. Both of these options will allow you to make a larger sample if that’s your thing. Larger samples may be necessary for more complicated weaving patterns or to also test out some other weaving parameters (more on that later.)
If you bought your yarn from an online yarn store then make sure to check out the information that is listed under the yarn that you bought. More than likely it will give you a recommended warp sett for your weaving.
If you don’t already know the EPI, then make your mini-loom to figure it out and then you can use that same sample to count your PPI.
Either way, make sure to weave up a few inches before counting how many wefts or picks can be found per inch of weaving. While technically you should be able to just weave up a 1 inch square to determine both EPI and PPI, I recommend giving yourself a little more to work with since it doesn’t take that much longer to weave a 2 inch square!
This will give you the most accurate count because it will help to eliminate any inconsistencies in your weaving. For example, sometimes you beat heavier than other times and this can affect your PPI.
Another note, is that it is generally best to always count your PPI while your weaving is still under tension. This will be the most accurate and easiest time to do this since it hasn’t relaxed yet and everything is sitting exactly where it’s supposed to.
The example I have above shows my EPI loom set up for 6 EPI. With the yarn that I am using, this weaves up weft-faced. After weaving 2 inches for my sample I counted the amount of picks that I had in the 2 inches and divided it by 2 in order to get my PPI. So this 6 EPI tapestry has a PPI of 32.
As you can see, your weft-faced PPI will tend to be pretty high because of the amount of compression inherent in the weaving. So while a balanced weave may use more warp, your weft-faced weaving will use more weft.
Things To Keep In Mind
Your PPI is not only important for figuring out how much weft yarn you need – it is also important for determining the drape of the fabric or weaving you intend to make.
The more yarn you have per inch of your weaving, the thicker and stiffer the weaving will be. You can play with the PPI manually as you weave to manipulate the way the fabric will behave once it is taken off the loom. Again, samples are incredibly important for this! Make sure to weave a slightly larger sample if you are wanting to test the way it drapes. You will have an easier time determining how it will behave if you have more to work with.
When You’re Weaving
In general when you’re weaving, you will want to be consistent. If you are striving for a specific PPI, it is even more important.
Just like when you are weaving up a sample, beating differently as you weave is completely normal. Trying to be as consistent as possible, though, will help you maintain the correct PPI and will give you the most even weave. This will also make sure that your weft yarn measurements are correct!
That being said, if you are going to be very close to using the exact amount of yarn that comes in a skein or cone then you could always buy another! This will ensure you have enough even if you beat inconsistently and make sure you have enough for samples.
Plus, more yarn! Yay!
If you’re looking for a way to make sure you get the right amount of yarn each time and make sure your weaving behaves the way you want it to, then knowing the PPI is an important step in that process! Don’t forget if you’re planning a weaving project then I go through the whole process with you in THIS post or click the image at the beginning of the post to get the e-book. You will get to download and print it for your own use (it also includes an exclusive weaving planning worksheet!) plus some information not found on the blog!
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