Before you order a home decor fabric for your own window project, you’ll need to first calculate the yardage needed. If the fabric is a solid, then it’s an easy task.
But if the fabric has a pattern, guesstimating is the worst you can do. Home decor fabrics are introduced and discontinued all the time. Fabric stores themselves choose to stop carrying certain fabrics to make room for new inventory. And even if you’re able to back-order, don’t be surprised if it takes weeks, even months in some instances, to get a fabric.
The bottom line is this – you’ll need to calculate the yardage right the first time. But before you do that, you’ll need to understand how fabric pattern repeats work.
This blog post helps you do that, no matter if your curtain style is a drapery panel, Roman shade, or window valance. The rules are the same for any style.
Width On the Bolt
First, know that most home decor fabrics are 54 inches from the left selvage to the right selvage. A selvage is talking about the edges that are around the usable (printed) part of the fabric.
This 54-inch width is just an industry standard that has been set a long time ago and makes the fabrics easy to manufacture and display on the bolts.
A typical fabric display at my local home decor store.
Sure, some fabrics may be 58 inches wide and have no clear selvage, while some other fancy, embroidered ones may only have 51 inches of usable width. In some rare occasions, the fabric pattern may be railroaded (turned 90 degrees). Most fabrics “run up the bolt,” meaning that the fabric pattern continues to repeat lengthwise as the fabric is rolled out on the bolt.
A railroaded fabric, on the other hand, doesn’t do this. It’s great for wide window projects like valances or shades for double or triple wide windows, but it won’t work for drapery panels. But generally, a 54-inch width with a pattern that “runs up the bolt” is the norm. Keep this in mind.
Pattern Repeats
If your fabric is solid, this shouldn’t be a concern for you. But if the fabric has a pattern, you’ll definitely want to understand fabric repeats before you even start calculating the yardage.
There are two types of fabric repeats – a vertical repeat and a horizontal repeat. Basically, this is a measure of how often a particular pattern repeats in either direction.
This large-scale fabric has a vertical repeat of about 17 inches, as marked by the x.
Example of vertical and horizontal pattern repeats on a fabric.
Horizontal fabric repeats are a factor of the overall width of the fabric. For example, if you were to keep dividing the number 54, you’d realize that it’s common for a pattern to repeat 1, 2, 3 or even more times from the left to the right of the fabric. This would translate to a horizontal repeat of 54, 27, 18 inches, and so on.
Of course, this could break down further, and some small-scale patterns can have tiny repeats of half an inch or less. Here are examples you may commonly come across:
| Fabric Width | Pattern Repeats | Horizontal Repeat |
| 54″ | 1x per width | 54″ (usually goes with a half drop vertical repeat) |
| 54″ | 2x per width | 27″ |
| 54″ | 3x per width | 18″ |
| 54″ | 4x per width | 13 1/2″ |
| 54″ | 5x per width | 10 3/4″ |
| 54″ | 6x per width | 9″ |
In the other direction, there is less restriction on the vertical repeat since each fabric is made in rolls of multiple dozen yards. But usually, it’s rare to find a vertical repeat that’s more than 36 inches in a home decor fabric. Also, large patterns usually command higher prices.
The (Inconvenient) Half Drop Pattern Repeat
Some fabric patterns repeat only once per the entire width of the fabric. So, these fabrics would have a horizontal repeat of the entire width of the fabric, which is 54 inches for most. As far as the vertical repeat is concerned, it isn’t uncommon for the entire pattern to repeat by about half on each side of the fabric.
You’ll often notice a clear zig-zag pattern on the fabric. This is called a half drop vertical repeat. It can be inconvenient. You may notice you have to skip ahead a lot when making valances or are trying to match the pattern on a double wide drapery. If you want a flat window treatment that’s wider than 25 inches or so, you’ll need to master the art of pattern-matching. While large half drop patterns may leave a lot of fabric wasted, the reason they exist is to create an oversized fabric pattern.
For example, if you have a large living room or a formal dining room with tall ceilings, and are looking for large toile, flower, or geometric patterns to prominently be displayed on your window treatment, a fabric with a half drop repeat is a clear choice. Let’s take a look at an example of a half drop pattern repeat.
In the picture above, notice how the patterns repeat in each of the white boxes. Also notice the circled floral section that repeats in a zig-zag fashion. The fabric pictured is about one yard, but what could you do with it when you have a half drop repeat like this?
We created this simple medallion valance using about a yard and a half of the fabric. It worked because each of the flat swags needed to be cut only 24 inches wide, which was perfect to center each of the flowers. The 24-inch cut sections were small enough to not be affected by the half drop repeats, so we didn’t have to skip any fabric in the process.
However, if you’re trying to create a window treatment that requires some sort of centering of a pattern across a wider section, you may realize it hard to do with a fabric like this. For example, creating a valance or flat Roman shade about 27 inches of wider will be difficult to do, unless you just don’t care about the specific placement of the large patterns. If you do care about the fabric placement, you’ll have an added seam that you’ll have to pattern-match.
Example Yardage Calculation for Custom Draperies
When it comes to drapery panels, you’ll have to take great care to match up the patterns. Let’s say you’re creating two drapery panels on a window about 40 inches wide. Here’s how that would roughly look in our workroom: We’ll probably advise a customer to get a curtain rod about 55 to 60 inches wide, to make the single window appear larger.
If the customer has a 9-foot ceiling, we’ll advise to install the draperies right under the crown molding of the ceiling, with the bottom hem of the drapes slightly touching the floor. That might translate to a drapery length of, say, about 107 inches or so. If the draperies are to be pleated on the top header (like pinch pleats, for example), each drapery should ideally be about a width and a half of the fabric. We like our drapes to be both lined and interlined, but draperies with lining only will have sufficient volume in this case.
Fast forward all these small details, we’ll need to cut 3 sections, each measuring about this much:
- 2 sections, 54 inches wide by 123 inches long;
- 2 sections, 27 inches wide by 123 inches long (meaning, one 54-inch wide section, cut in half).
If the fabric is solid, you could get away with about 10 1/2 yards for the total yardage for these two custom curtains. But if there is a large pattern, you’ll have to skip some fabric in between each section, making sure to pattern-match. Using the example of the large-scale floral fabric from above, our workroom wouldn’t tackle this custom project unless we had at least 13 continuous yards of fabric secured first.
Once complete, we’d have two draperies, each about 78 inches wide once spanned out at the bottom hem and about 27 to 35 inches wide at the top header once the pleats were created, depending on how much gather the customer wants at the top.
Pattern-Matching Your Fabrics
I’ve already touched on this, but it’s important to match patterns across the seams whenever the fabric sections are joined. Most beginners are afraid of “losing” fabric here, so they have a tendency to leave too much here when cutting. Unfortunately, once the fabric is sewn and turned inside out, you may be disappointed to see the same section of the print repeat twice across the seam.
Pattern-matching is a skill that can sometimes be beginner’s luck, but more often than not, it takes time to develop. Buy more fabric and practice first if you’re a beginner.
A good pattern-match across seams.