Roger Morph 
In this article I will show you how to make a fabric curtain liner from scratch. A fabric shower curtain liner serves as the barrier between the shower-water and your expensive bathroom tiles or bath tub, preventing water from being splashed out of the tub/shower area. This “curtain” is not only functional but also adds a pleasant visual effect to the bathroom. When you buy a new shower curtain, it usually comes with an insert of some sort (usually white plastic like in my picture). However, this is not how they are made originally.
The following instructable will show you how to make your own fabric liner. It only requires basic sewing skills and about $20 worth of fabric.
Materials needed: Fabric (Amount varies depending on the size of your shower/tub, but about 1 yd per linear foot), Thread, Sewing machine or needle and heavy duty thread, Ruler, Scissors
First measure the inside perimeter of your bath tub/shower area. Divide this measurement by two to determine how wide your shower curtain should be. Cut two pieces of fabric this width and then cut them to the length required by adding about 10 inches for seam allowance (the part that will show, but I failed to take a picture of it). Fold each piece in half along the length and sew up both sides. Turn it right side out to see the final product.
Add grommets (optional)
Adding a metal or plastic piece around the top of your shower curtain is great for hanging it from hooks on the ceiling or rod. Grommets are used to reinforce fabric where you attach/remove it from things, so this is a good place to add them!
You can buy them at your local craft store, but if you have any sort of fabric with a hole it probably already has grommets printed on it.
Mark where to put the holes for the grommet. I prefer to use solid rulers since they are easier to see through than clear ones. Place the ruler where you want your grommet and mark the 4 dots with a pencil. Be sure to leave about 1/8 inch on each side of the ruler as this is how thick your grommet will be (i used a combo square to make things easier).
Pin one side of the grommet onto where you marked it. Make sure that there is at least 1/4 inch of fabric around the marked area. Sew a straight stitch from one hole to the other, stopping about every 1/8 inch to make sure that your thread is holding up well.
Remove pin and place grommet over this stitching line (it should be on the inside facing you). Again, use thick objects like rulers or paint can lids to push it down.
Conclusion
If you are concerned about the sturdiness of the thread, you can always use heavy duty thread to sew around where your grommet will be! This also prevents tears in the fabric that could happen if it is pulled on too hard. (I used this earlier when I made my first curtain and it worked out great…until I hung it in my shower and pulled too hard!)
Attach your curtain to a rod or hooks using the grommeted section! (optional)
This part is so much easier if you have done the rest of this project with heavy duty thread, but I do not recommend working with metal objects while you are tired so I did it with regular thread and had to redo the whole thing…twice.
If you have curtains with loops, you can attach your fabric shower curtain liner to them by sewing a straight stitch around the perimeter of the product.
