In general, the most important things to consider when choosing fabrics for the Electron Layette are weight and stretch. For weight, you can generally use your gut – feel the fabric and think “would this be appropriate for a hat/bib/sweatshirt/pants?”.
For the Electron Layette hat, the most important thing to consider is stretch. The hat needs to stretch to comfortably fit onto baby’s head. The pattern calls for at least 30% stretch though the more stretch the merrier. Jerseys (left) are a good choice but you can also use fabrics like ITY knits (right). You probably want a fabric that has recovery to it – when you stretch it, it should spring back – so that it stays well on baby’s head.
The Electron Layette drool bib can be sewn from either knits or woven. Stretch doesn’t matter here, though fabrics with stretch will be a little harder to sew with so if you are a beginner sewist, you may want to pick a woven fabric. You want the fabric to be fairly lightweight so that it’s comfortable on the neck. Quilting weight cotton broadcloth (left) is good choice for wovens and t-shirt weight jersey (right) is a good choice for knits.
For the Electron Layette sweatshirt, there a bunch of different options that would be appropriate. The most obvious are sweatshirt fleeces. The thicker or loftier the sweatshirt fleece is, the harder it will be to crisply sew the details. Similar to sweatshirt fleece, you can use a french terry – quite like sweatshirt fleeces, it has loops on the wrong side instead of a brushed fleece. If you want to get a bit non-traditional, you can use fabrics like scuba, ponte, or sweater knits – just pay attention to their weight and stretch. The pattern calls for 20% or less stretch because it’s designed to hold its shape, but I had pattern testers use fabrics with more stretch and it works just as well, you just get a softer look.
For the Electron Layette pants, the most obvious choice is a t-shirt weight jersey, but you can easily go up or down in weight. For summer, you can use a lighter-weight knit like a tissue knit or a burnout (far right). Going heavier, you can easily step up to an interlock, a jacquard, ponte, or even up to a sweatshirt fleece or french terry (far left). If you want to make a cold weather pant out of a thicker fabric, you will probably want to go up a size in width (I’ll show how in detail in a sewalong post). The pattern calls for at least a 30% stretch so, while you can use a variety of weights, you want to make sure you have enough stretch that you can easily pull the pants on and off baby and that they will be comfortable for baby to wear.
I hope this gets you excited to pick out fabrics for your Electron Layette! Let me know if you have any questions.