I’ve recently had chats with several folk who ask about the number of threads they are supposed to be using when working linear blackwork (fills or the strapwork designs commonly done in double running or back stitch).
I attempt to answer, and the answer isn’t a plain, flat “always.”
There are several factors to consider for counted work. First there is the ground fabric. Some people favor purpose-wovens like Aida, Hardanger, Monks’ Cloth or Anna Cloth. These are made with large, prominent holes for easy counting. They come in a variety of stitch-per-inch (or cm) sizes. They range from 9 to around 22 stitch per inch (aka “count”). The more stitches per inch, the smaller those stitches are.
Other types of grounds are also used, with even weave (or near-even-weave) being less popular than the purpose-wovens. These grounds are flat tabby woven fabrics. They do not have a system of prominent holes for easy counting – to use them the stitcher counts the threads of the weave itself. Most sold specifically for embroidery are more or less true and square, with very close equivalent measurements of the threads running the length of the bolt (the warp), and across the bolt (the weft). The measurement of fineness of weave for these fabrics is expressed as threads-per-inch (or cm), and they can range from around 20 threads-per-inch (tpi) all the way up to 50 tpi or more. Stitchers generally work over a visualized square of 2×2 threads, so a 24 tpi piece of even weave would yield the same 12 stitches per inch as 12-count Aida, but the holes between the threads would be far smaller and less obvious.
Now aberrations exist. Not everyone works over 2×2 threads on even weave, and it is possible to work counted styles on anything you can actually see well enough to count, whether or not the warp thread count is even close to that of the weft. But in general, the ground cloth world splits into purpose-woven/larger more prominent holes; and (near) even weave/smaller, less evident holes.
On to thread.
It’s all over the map. The most common thread used today is standard 6-ply embroidery floss, but there are hundreds of other options. And even plain old embroidery floss is NOT uniform. Not even if they are of the same fiber. For example, DMC and Anchor cotton flosses have very slight differences in ply thickness, with the DMC (most of the time) being ever so slightly thicker than the Anchor. And even within a line, there can be variation because different colors take up dye differently, or because of visual impact of the color used (a dark thread will often appear heavier than one of a lighter color, even if there is no actual difference between them). And if you begin comparing across fiber types/spin types even more complications ensue – One ply of DMC cotton 6-ply is thicker than one ply of Au Ver a Soie six-ply silk, for example.
Here are three examples on even weave (please excuse me for not having Aida samples to hand – I don’t use it.)
First, here is an example of 32-count even weave linen (16 stitches per inch), worked with two strands of a six-ply silk – a small lot product produced by a boutique hand-dyer. Note that the individual stitches are about as thick as the ground cloth’s weave. They fill the holes into which they are stitched completely, and in fact are a bit jammed up into them, making intersections just a bit muddy and tight:

Here is that same ground, worked using just one ply of the same thread used in the previous sample.

You can see that the stitched thread is significantly thinner than the ground cloth’s weave, and that corners and angles are sharper. But the stitching thread still fills the holes, and doesn’t “rattle around” in them. There is another difference – the stitching doesn’t look as even. It’s harder to achieve a uniform appearance with skinny threads, but the difference that shows up in extreme close-up is less evident at normal viewing distance.
Which is better? It depends. One or two threads are both suitable for use with this fabric. Do I want a light and lacy effect? Do I want something darker and more strident? Should I accent the close, dense and angular aspect of a design (as on the left), or should I try to bring out the curves and delicacy (on the right)?
By contrast with these two balanced examples, there’s the piece I am working on right now. I am working the black bit with one strand of standard DMC 6-ply cotton floss. It’s about 14 stitches per inch (28 threads per inch).
Obviously the count on this stuff is skew. It’s not true even weave. Were it so the enmeshed ovals would present more like circles. But it’s close enough so stitched-it-will-be. Look closely at the size of the thread and the holes in the weave. Even though the black thread is slightly thinner than the fabric’s threads (like the lacy sample above) – look at it in comparison to the gaping holes between the fabric’s threads. It’s tiny and spindly. It’s lost. It wobbles. Corners are extremely difficult to keep square, angles are being pulled, and the threads that make up the design do not present in nearly as neat rows as the previous example. This same ground, with two plies of DMC? Much better looking:
In this case, I would advise AGAINST using this particular ground with only one ply of standard floss. It’s holes are too big. I’ll finish out my black interlace mask pieces, but I won’t be using a single on this stuff again.
And mixing thicknesses? It’s a great tool. Jack Robinson – the UK’s Blackwork Patron Saint (now of blessed memory) – was a strong advocate for both historical and modern pieces that mixed thread thicknesses.
Here are a couple of examples of doing so, from my own work. I find it of special use for giving modern-style voided pieces a lighter background touch, although I have also used it to de-emphasize veining inside particularly complex leaves on non-voided work.
First: In addition to using a different background pattern for each, the yellow ground on the left is done with one strand of DMC floss, and the yellow ground on the right, with two so you can see the density.

Second: Foreground and background in the same color, but the foreground is worked with two strands, and the background with one.

Now how does this work out on Aida? Again, I apologize for not having samples to hand. I don’t use it. The reason why I don’t is that I find the holes to be a visual distraction that take away from the presentation of the work as a whole. I’ve seen magnificent stitching on Aida, and I throw no shade on those who prefer it. But to me those holes can be way too big for the thread choices many people use. Like my wobbly sample above, the threads have too much play, and even tension without distortion at the corners or avoiding jaggy lines can be more difficult to control because the holes are big compared to the stitching thread.
For myself and my own work aesthetic, I prefer a well-stuffed hole (sometimes bordering on over-stuffed), and select my threads accordingly. One strand on Aida? I’d suggest two. Or three if it’s 12 or 14 count. But as in all things, my practice is not a yardstick by which you should measure your own preferences.
Look closely at your product. Try to understand why the threads behave as they do. Are you happy with your stitching? Think about your design goals. Even if you are interpreting a pattern by someone else there is plenty of scope in there for your own design choices. Thread thickness and proportion to the ground and to the size of the holes are just more variables you can play with to make any piece visually distinctive and uniquely yours.
Remember my family’s latke rules. Every family’s latkes are different, and every family’s latkes are the best. The same goes for stitching.
Fabulous as always! Thorough, considered and concise. And of course with lovely examples. Thank you!
[…] Kim Salazar has another awesome blog post, this one on thread thickness…. https://string-or-nothing.com/2020/11/06/blackwork-thread-thickness-and-grounds/?fbclid=IwAR0KgOu5X… […]
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