I saw this pillow for sale and would like to make it with my own fabric, in a different color. How can I replicate this look? I have a sewing machine and moderate confidence in my by-hand skills as well...
You cant sew fabric like that from normal flat fabric. If you have the fabric, you can sew it together as a pillow. But your question seems to be about making the fabric itself. To make fabric like that, you would need to weave it on a loom. (If you have never woven, my answer will make no sense at all.)
Here's how to do it.
Cast on a very sparce warp; about 3 threads per inch by the looks of it. These are the thin threads running horizontal in your picture. The weave you would do is called a log cabin weave. For your weft, get two different kinds of bulky yarn. You will alternate in a pattern like this. A pedal: go left with the first color. B pedal: go left with the second color. A pedal : go right with the first color. B pedal: go right with the second color.
Repeat this pattern throughout the whole fabric. Make sure not to beat the weft down too hard. This is a very loose weave.
I agree with margalo's assessment that this pillow was most likely created with a specially woven bumpy fabric, rather than sewn from flat fabric.
However, in the spirit of craftiness -- you could try creating a similar bump pattern with smocking. This won't look exactly the same, but it is a way to create a 3D texture from flat fabric by sewing. Smocking is typically done by hand, by marking a grid on fabric and then drawing the points together in a particular pattern with thread.
For example, this bobble cushion has some of the elements you are looking for:
Smocking is usually done with lightweight wovens and gives them crisp and even gathers. For this pillow, I would suggest trying a thicker, soft fabric. You might even be able to use a (stable) knit. This is because the original pillow is uneven and bumpy, with thicker bobbles (plus, it will probably feel nicer).
Finally, I know you asked about sewing, but if you are willing to crochet or knit, a third option would be to alternate rows/columns of bobbles and rows/columns of flat stitches. Again, not exact duplicate, but a similar texture on the large scale could be achieved.
This fabric is definitely created by weaving, but it really shouldn't be that difficult to create something similar even as a beginning weaver. First, turn your picture 90 degrees. The thin thread that goes from the top to the bottom is called the "warp". The two thicker "yarns" that go from side to side are called the "weft."
You could create something similar to this with a picture frame loom (go out and buy a cheap wooden picture frame without any glass in it) or a cardboard loom. Basically, the way weaving works is that you anchor multiple strands of your warp thread at the top and bottom of a loom (called "warping" the loom), and then once you have those strands in place, you weave over and under the warp threads with your weft yarn.
Your weaving will be done by alternating the two different types of weft yarn--both of which look to be made by using strips of fabric. You could make something like the thinner strips with t-shirt yarn, which is basically made by taking a stretch knit fabric, cutting it into long strips and pulling it at each end, which will cause it to roll into a little tube
The thicker weft looks like wider strips of a lightweight fabric (maybe a cotton gauze) that has been bunched together to make something that resembles a cord/ribbon.
Start weaving across with your t-shirt yarn, and try and keep the tension even all the way across, so that the yarn seems to lay fairly flat all the way across.
Then, the next row, use your gauze fabric yarn, going under where you went over on the last row, etc. This time, though, don't pull this "yarn" tight as you go. You want the tension to vary, so that you get the uneven bumps (sometimes you pull this yarn flatter between each strand of warp yarn, and sometimes you leave a larger puff of fabric).
I suggest googling "weaving on a picture frame loom," or a "weaving on a cardboard loom" and "making t-shirt yarn." I would add some links, but I need to build up my reputation first.
May still seem like a lot of work, but it really is a beginner weaving project, and the lumpy bumpy nature of the fabric will hide most of the mistakes that beginning weavers usually make.
A couple of additional comments--whenever you remove a piece of cloth from a loom, it pulls in on the sides. You will need to make sure that your warp is wide enough that your finished piece will be the width you want for your pillow, plus seam allowances and selvedge. You will have to experiment a bit to determine how much wider that should be, as the draw-in is completely dependent on the materials used and the specific weaver.
Once your cloth is woven, use a zigzag stitch or double stitching to sew around the edges of the finished piece, like you would do when stay stitching a collar. This will stabilize your piece and you can cut outside of the stitching to make a square that is the size you want for your pillow.
To me it looks like a weave with an extra think yarn for the bumpy bits.
You might be able to replicate it by taking a loose weave fabric and using embroidering to work the thick yarn in. (For which you will need to make space by pushing the other yarn of the basic fabric out of the way.) You will have to experiment how to get the same effect in the embroidering, I guess it is over 2, under 1, over 5, under 2, and so on.
After that you can sew the fabric onto the cushion as usual.
I would not bother, just getting a new fabric that you like will be much faster and less likely to go wrong.
This appears to be woven of three different "diameters" of material. Two of these "diameters" appears to be similar to what one would create by taking two different widths of material, as is the method in creating rag-rolled rugs. The third "diameter" appears to be multi-strand yarn being used to bind the other two together into rows.