The most common shower curtains sold are made of vinyl with very inadequate reinforcing around the hole used to hook it to the curtain rod. The result is that rather quickly the vinyl stretches and breaks through. Now this process accelerates when you have a wife like mine who scrubs the curtain dry after every use (no male would ever think of subjecting the curtain to such abuse).
For a long time my wife would simply staple the vinyl back together, with more and more staples, so I finally got to testing glue and plastic to create reinforcing washers. I got it to work pretty well by cutting circles out of hard plastic shell packaging that I would recuperate from the recycle bin - but although successful and decent looking that was a bit time consuming.
The raw materials
One day, while working in the office with good old fashioned hanging files, it occurred to me that the file index label holder was very clear rather strong plastic and already moulded into a convenient clam shell shape. From there it took very little experimentation to establish my "permanent" shower curtain repair -- all with the simplest of household tools -- as you can see in the second photo.
Clean
Work with a new curtain, or clean off any dirt from the old curtain on both sides of the curtain and both sides of the tear out.
Prepare the reinforcing plastic
Cut off the lower insert tabs of the plastic label holder. Force the label holder slightly open -- not so much as to weaken the plastic, but just enough so that it will stay open while working with it. Apply a smear of Krazy or other "Super Instant" glue to both inside faces of the plastic label holder.
Clamp into place
Place the reinforcing patch over the edge of the curtain with the hanger hole in the centre and squeeze it shut. Put clothes pins on each side of the hole to assure a tight fit. I leave them in place half an hour but technically you could do less. The reason I wait a bit is that the plastic wants to open back up and I want to be sure it is well stuck into place to prevent that. Clothes pins have plenty enough clamping power to keep all the surfaces in contact, which is all that is required with super glue.
Create a hook notch
Use a paper punch to punch out the hanger hole. Since the label holder generally fits perfectly half way over the hole, this will simply punch out a notch in the stronger plastic. Now the metal of the hanger will lock into this notch and not slide from side to side to stretch the vinyl.
Preventative maintenance
This patch doesn't wear with the pull of the hanger hook and distributes the pulling force over a wide enough area to prevent any further damage to the curtain -- all while being almost invisible and not interfering with the ability of the curtain to slide and fold on the curtain rod. The mechanical durability of the curtain will now surpass the aging and fading limits of the curtain -- meaning that you only replace it when you are tired of it, not when it starts to fall down.
It works so well that I have decided to do this to the entire curtain before it is ever installed -- I think you call that preventative maintenance. The only problems are that I won't get the opportunity to do it again until the sun fades the curtain presently installed -- and my wife now claims that I can no longer use the excuse of preserving the curtain by my not wiping it dry after every shower. Is there something that I missed here?