A knife pleat sounds dangerous, but it is actually one of the easiest and, we think, prettiest members of the pleat family. In a knife pleat, the folds are pressed to one side in the same direction, which is why they are also sometimes called side pleats. More than likely, you’ve seen knife pleats on a garment; like those great tartan kilts bag pipers are known to wear… with or without something underneath.

Using a pleat, regardless of type, is a way to gather fabric to create fullness. You see the technique most often on garments, predominately skirts. However, it’s a great option as a border effect along the hemline of a garment or around a pillow. Pleats are timeless, and can be adapted to any type of project. The resulting visual effect can become a true focal point, taking the project to the next level.

Earlier this week, you learned How to Make A Box Pleat Or Inverted Box Pleat. Today, you’ll soon be a knife pleat expert. And, down the road, be on the lookout for wave pleats, accordion pleats, sun-ray pleats and more.

We used knife pleats in one direction (facing down) on our unique tuxedo pillowcases.

Fabric and pleats

The type of fabric you select is an important factor in both the crispness of your pleats as well as the size. Natural fiber fabrics lend themselves better to pleats than their synthetic counterparts. Fabrics such as cotton, wool or silk will hold pleats when pressed. Synthetic fabrics require more work to hold pleats in place.

In addition, the weight of your selected fabric is also a factor. Finer fabrics, such as handkerchief linen are best for narrow pleats where bulk is not an issue. Heavier weight fabrics, such as wool are better suited for wide pleats.

If you’re not using a pattern with fabric suggestions, how do you know what size to make your pleats? We recommend testing a sample of your fabric with markings at various intervals to see what looks best to you. Start with a 1″ fold and go up or down from there.

Marking for knife pleats

The knife pleat is considered to be the most basic pleat. You create a fold in the fabric at a predetermined width, and press in one direction on the right side of the fabric. Unlike other types of pleats, knife pleats always travel in a gang. Just one or two would be considered more a tuck than a pleat. Because you are working in multiples, you need to mark your fabric very accurately.

To start, you want to have the proper marking tool for your fabric. This is sometimes easier said than done, but do not fear, we are here to guide you. Your favorite sewing supply retailer will likely have quite a selection of fabric marking pens, pencils, chalks, etc. How you determine which will work best? Try them on fabric scraps! The ultimate goal is two-fold; one, you need to be able to see the mark on your chosen fabric, which means a dark line on light fabric and a light line on darks; and two, you must make sure the marks can be easily removed from your selected fabric. It’s a good idea to have a few different types of marking tools to choose from in your sewing basket, because often one type works better on one fabric than another. Below is a picture of a few of the marking tools we have in the S4H studio.

Guide lines for knife pleats ultimately have to show up on the right side of the fabric. Depending on the fabric type, marking tool, and/or project, you may have to draw your marks on the wrong side then use thread basting to see them on the right side. Or, you may be able to simply mark the pleat lines on the right side. Below, we show you how to do both.

NOTE: If you’re using a commercial pattern, you will need to take added steps to mark your fabric because you will have the paper pattern between you and the fabric. You can use a variety of methods which may include a tracing wheel and transfer paper, pin markings, and/or clipping at the fabric edge. The key is not to move the pattern piece too much so as not to skew the placement of the pleats.

Marking on the right side only

1. The markings for all pleats, regardless of type, have two fold lines: one for the outside fold and one for the inside fold. In addition to these two lines, you also have a placement line and sometimes little arrows that point in the direction you will fold or press the pleats. If you look at a commercial pattern, the fold line is usually a dotted line and the placement line is a solid. If you are following a tutorial or designing something yourself, we recommend using a similar approach.
   NOTE: In our example below, the pleats are 1″ wide, which means we mark the fold lines 1″ apart, and the placement line 1″ from the inside fold line. Repeat this process so there is a line marking every inch. This same pattern would be followed if your pleats are larger or smaller. The key is to keep all your lines even.
2. Place your fabric RIGHT side up on a flat surface large enough for your fabric piece.
3. Working on the right side of the fabric, use a marking tool and ruler to mark the fold lines with dotted lines and the placement lines (where the fold will be pressed flat) with solid lines. If you need additional help to differentiate between the two, you can use two different colors.
   
   NOTE: Some experts recommend making small snips in the edge of the fabric at the fold lines and placement lines in addition to marking.
   
4. Pinch the fabric up so the first dotted line (the outside fold line) is at the top of the fold and the second dotted line (the inside folde line) is at the bottom. Fold towards the placement line.
   
5. The bottom or inside fold line will be your guide to keep your pleats even in size. Pin to hold each pleat in place.
   
6. Continue in this manner until you have folded and pinned all the pleats.
   
7. Transfer the pleated panel to your ironing board for pressing (we have some notes on pressing below).

Marking on the wrong side with basting thread

1. Sometimes, you simply can’t mark from the front without ruining your project. In this case, you can mark from the back and use basting thread to create guide lines you can see from the front.
2. Place your fabric WRONG side up on a flat surface large enough for your fabric piece.
3. Following the same steps as above for marking on the front, create all your guidelines on the wrong side of the fabric.
4. Using a hand needle and thread, run a long basting stitch through the marked lines. We used two different thread colors to differentiate between fold lines and placement lines.
   
5. Turn the fabric over to the RIGHT side to fold and pin into place exactly as you did above.
   

Marking pleats farther apart

If you’re wondering how knife pleats would look spaced farther apart, we can show you! To do this, simply leave more space between the placement line and the outside fold line of the next pleat.

In our example below, we spaced the pleats 2″ apart.

Pressing knife pleats

After you’ve spent the time to pleat your fabric, you certainly do not want the pleats to be comprised. Placing pins at either end of the pleat along the raw edges, and a few pins in between if your pleats are quite long, will help keep the fabric in place until you get it over to the ironing board.

Once at the ironing board, it’s never a good idea to press your fabric with pins in it! So, remove the pins as you slowly press your pleated folds. But, what if you have a large piece of fabric? Simply pin the fabric to the your ironing board cover.

One other detail to think about when pressing pleats is whether or not the pressed fabric folds will leave an indentation in your fabric. If you use a pressing a cloth, or brown paper, in between the folds as you press them, it will help eliminate indents.

Securing knife pleats in place

Once you’ve completed the pressing phase, you need to secure the pleats so the fabric piece can be sewn into your final project. For this, depending on your project, a simple basting stitch along one or both raw edges will hold the pleats in place.

Again, depending on the project, knife pleats can also be partially sewn or topstitched along the fold. This technique is often used on crisp skirts to secure pleats from the waist to the hip.

Conversely, if you’re sewing a knife-pleated skirt from a lightweight fabric, the pleats can be left to hang loose into soft folds from the waist. It all depends on the overall visual effect you are going for on the finished project (or finished garment in this case).

NOTE: If your pleated piece is part of a garment, any hemming should be done be prior to pleating. It can be done afterwards, but you would need to repress all your pleats.

Another accepted practice is to edgestitch each fold. When would you do this? If you’re using a lighter fabric and want the folds to remain in place (instead of becoming loose folds as mentioned above), edgestitching will help the pleats remain crisp at the edges. Remember, don’t baste across the raw edges with this technique.

You can also sew a knife pleat at the base of the folds, which will make the pleats become almost 3-D from your fabric. We used this type of effect in our Black & White Lumbar Pillow project. You’ll notice these knife pleats are spaced farther apart (as described above) instead of folded one upon another.

If you decide to get really creative, you could use a contrasting thread along the inside folds of your knife pleats for a fun look! (Of course, in our technique tutorials, we always use a contrasting thread so you can clearly see how to do the technique.)

Sample Creation and Instructional Outline: Jodi Kelly