I wanted a convenient place to hold the trimmings when cutting up meat, vegetables, fruits and seafood, without putting the trash bag in the sink, as it often got water logged or wet. At the same time I needed something that wouldn't take skin off each time someone walked past, so this was designed from scratch to flip up, slide into place to hold up any used supermarket/ grocery plastic bag.

You can place both holders (brackets) as close or far apart as your bags allow. This is still work in progress as I'm not entirely happy with the holders (see video). While you can double loop for bigger bags, I am working on a better design to hold bag handles at varying points. Stay tuned..

The brackets fit any countertop with an overhang lip of at least 30mm.

Printed parts: one of each mount and two of the bag holders (flip one around for installation).
Screws: 4 flat head self tapping screws (i used 6X 3/4") and 2 M3*12mm screws (to lock the bag holders.

Installation (find an ideal location first):

1. Find hanging limit of one arm along the countertop's underside (avoid colliding with opening cupboard doors etc)
2. Drill pilot holes through the holder (bracket)
3. Install 2 x self tapping screws
4. Install bag holder, followed by M3 screw to secure it
5. Hook up a bag, with the other holder and arm free-moving, decide how far apart you want that installed
6. Repeat steps 2 to 4

https://www.youtube.com/watch?v=lNZGxqhYW7M