Working with water resistant fabrics can be really fun if you're looking to sew a makeup bag, a lunch bag, or a picnic blanket! But sewing these kinds of fabrics is really different than sewing with regular woven fabrics because they are plastic or covered in plastic.
First, let's understand what each of these are. Vinyl can be everything from a thin shower curtain to a heavyweight vinyl that you find on car seats. Oil cloth is a woven fabric (usually cotton) that has been treated with linseed oil to create a water-resistant surface. Laminated cotton is regular woven cotton on the wrong side and is coated with a plastic finish on the right side. Now that we know which is which, here are a few helpful tips to get you on your way to your next project!
It's important to keep in mind is that plastic is sticky. Have you ever bought a vinyl shower curtain? If so, remember what it was like to unfold it from the package wrapping? That is exactly how these fabrics are when you're trying to sew them too! So in order for the fabric to glide through your machine, you have to think about the presser foot and the foot plate.
The best foot to invest in is a Teflon foot. Just like how a Teflon pan is non-stick, so is a Teflon foot. The plastic coating on the fabric will glide under the foot with ease. However, if your foot plate is metal, the Teflon foot will only help it so much, since the vinyl will stick to the metal. There are a few ways to handle this. First, you can use a tiny bit of baby powder under the fabric to help it glide. Just be careful not to use too much and to wipe it off when you're done. Second, you can use a bit of tissue paper under the fabric, sew through all the layers, and then tear it off afterwards. Lastly, you can cover the foot plate with scotch tape, being careful not to interfere with the feed. These are all great when sewing with vinyl or oil cloth, but working with laminated cotton can be easier since one side is actually cotton. Just make sure the cotton is facing the foot plate and the plastic side is facing the Teflon foot, and if will go through the machine perfectly.
After you consider how the fabric will get through the machine, you need to change your needle. Vinyl, oil cloth, and laminated cotton are all different, but they all need to be sewn with a wedge point needle, which is also used when sewing leather. The needle is angled at the bottom and pierces through the plastic. A regular needle is smooth to the tip and doesn't have the same power as a wedge point.
Lastly, these types of fabrics do not like being stitched more than once in any given spot, so back stitching is not really an option. Leave yourself some long tails on your threads at the end of each stitch so you can tie them into knots after stitching to lock them in place. Also note that none of these fabrics will be waterproof, since you've now made holes in them. For that, you will need to buy a sealant to close up the holes with.
Good luck and I hope this removes the fear of working with water resistant fabrics!