Today, we’re showing you how to make the Calder Pants & Shorts out of a knit fabric—such as by making a comfy pajama set! This hack is super simple and easy for beginners and advanced sewists alike.

The Calder Pants & Shorts are stylish wide-leg trousers designed for drapey woven fabrics. We usually don’t recommend using knit fabrics on woven patterns (and especially not vice versa!) because the fit won’t be quite right, but the Calders are loose and flowy so a knit fabric can certainly work.

When you make the Calder out of knit fabric, it can resemble loungewear, which inspired us to make a sleepwear set! We’ve paired the Calder Shorts with a Concord T-Shirt here, but the Cedar Dolman Top would look equally adorable with matching shorts. Or you could use the Tobin Sweater in View C (the open neckline) and play with a little color blocking to use up spare jersey—that would look so darn cute! Okay sorry, getting distracted here. Back to our knit Calder hack.

Making the Calder Out of a Knit Fabric

When it comes to making the Calder out of a knit fabric, there are two adjustments we recommend making. But first, let’s chat about some of the features of the Calder that will help us understand why we’re making these changes.

The Calder has a flat front and elastic back waistband. The front of the waistband is made up of two separate pieces of fabric, both of which are interfaced and then sewn together—the inner piece becomes the waistband facing. This gives the pants their flat, polished look from the front.

The back waistband is one piece and is folded in half the long way, with the inner half becoming the waistband facing. A length of 2″ elastic is inserted into the back waistband after the waistband is attached to the legs of the pants and topstitched. Because the elastic is shorter than the back waistband, the back waistband gets pulled in for a comfortable back fit.

When sewing your Calder with a knit fabric, use a woven fabric for the front waistband facing (just the facing—the outer waistband can still be knit). This provides extra structure to the front waistband so that it doesn’t collapse while you’re wearing it or fold over (and stay folded) when sitting. Be sure to still interface both the outer front waistband (knit) and waistband facing (woven).

Since the waistband facing is not visible from the outside, it doesn’t need to match the outer fabric. I happened to have a scrap of quilting cotton that was just the right length for the front waistband facing and happened to be a similar color, but don’t fret if you can’t find a perfect match.

When sewing your knit outer waistband with the woven waistband facing, the knit fabric may have a tendency to shift a little. You can either just make do, or if you’re like me and you’re going to be photographing it and sharing it with the world, you can use Wonder Tape or baste the two layers by hand first to help keep them aligned.

I also hand-sewed the facing on the inside instead of topstitching from the outside for this same reason, and it resulted in a clean finish from the outside that I quite like.

When using a knit fabric for your Calder, you may also find that the legs become overly roomy, and that you want to take them in a bit at the sides. Depending on the drape of your fabric, the legs may look more flowy or structured. We recommend making a muslin using a similar weight/stretch fabric to test the fit before cutting into your final fabric.

One final tip for sewing your Calder using a knit fabric: sew your seams using a zigzag stitch or on a serger, as you do with other knit garments. However, you’ll want to stick with the seam allowances noted in the pattern instructions, and if you’re using the darted pear fit, sew your darts with a straight stitch. (Or skip the darts for a more relaxed fit.)

And that’s all that there is to it! Now let’s chat about making pajamas with the Calder.

Making a Pajama Set with the Calder

When making the Calder into pajama shorts or pants, you’ll want to follow the recommendations outlined in the previous section. Here are a few other things to take into consideration if you want your knit Calder to be comfortable specifically for sleepwear:

After I made my knit Calder Shorts muslin and put it on, I noticed that the waistband was more tight around my waist than is normally comfortable for me for sleepwear. I like my pajama pants very loose so that I can feel my most relaxed, and often loosen the drawstring as much as possible. Although the elastic of the waist was perfectly comfortable for my daywear Calders, I felt like I needed more room when sleeping/lounging.

Thankfully the solution is quite simple: cut a longer piece of elastic. How much longer is up to you—I started with a piece that was about 4″ (10.1 cm) longer than noted for my size, and then gradually trimmed it shorter 1/2″ (1.3 cm) at a time until the fit felt right for me. (I think I ended up going 2.5″/6.4 cm longer than the length for my size.) You can wait to do this until your muslin is almost finished, and then cut a longer piece of elastic and insert it into the back waistband. Pin in place with safety pins so that you can try it on without having to sew or baste it in place, then adjust as needed.

The final change I made to these Calder Shorts was to shorten them. By quite a lot, actually. This step is totally optional, of course. After looking online for pajama set inspiration, I knew that I wanted my shorts to be on the shorter side, so I cut them a few inches shorter than the pattern. I waited until the final step to trim them down even further. When all was said and done, my inseam was 1″/2.5 cm (with a 1″/2.5 cm hem). That sounds crazy short, but I think they look just right for pajama shorts.

Then I made a Concord T-Shirt with matching fabric to complete the set!

I used a size 12 in the pear fit for the Calder Shorts, and a size 12 E/F for the Concord T-Shirt. Thanks to quarantine life, my measurements have changed a bit so the fit of the Concord is a bit tighter than is to be expected. (Always measure before starting a project, especially right now! Rookie mistake, I know.)

I used an Art Gallery cotton/lycra jersey knit from fabric.com. It looks like it’s sold out since, but if you want to get this same look, keep an eye out to see if they’ve stocked more. (Or look for it elsewhere—we found similar listings at Hawthorne Supply Co and at Weave & Woven.) This fabric was a dream to sew and is very cozy to wear.

And there you have it! An adorable sleepwear set featuring the Calder Shorts.

What questions do you have about this hack? Do you plan to try it out? Let us know in the comments below, and be sure to tag you photos with #CalderShorts and #CalderPants so we can shower you with compliments!