This is really a very simple design to hold a roll of kitchen paper, designed to fit perfectly under a kitchen cabinet. The holder can be printed quite thinly while still being quite sturdy, so your cabinet doors still close normally and the holder sticks out through the gap between the door and the cabinet. Sliding the holders to the side would allow for longer or shorter rolls, and the prongs are tapered in order to make the holders fit very snugly. It is surprisingly solid!

The uploaded stl models are designed to fit tightly on a plank with a thickness of 16.3 mm, and hold rolls with a diameter of around 10 cm. However, if you open the included f3d file in Fusion 360, you can modify all parameters to make a holder that snugly fits your own cabinet. This model is really a good example of the advantage of 3D printing: it is a very simple plastic product, but no store would have a holder that fits your cabinets just right. My holder was printed in regular PLA, with a 0.6 mm nozzle, 0.2 mm layer height, 2 solid layers, and 15% infill.

To modify the parameters in Fusion 360, click on “Change Parameters” in the Modify menu.

You should see the following screen, and clicking on the “Expression” for any of the parameters will allow you to modify them. If you modify a parameter, you should see the model updating immediately. Simply export them as usual, and you're ready to print.

• holder_thickness is how thick the walls of the holder are all around. You should set this low enough that it fits in the gap between the door and the bottom plank of the cabinet, but as wide as you can. For me 3mm fit perfectly, I would not recommend going much lower than around 2mm because it will definitely impact the strength of the holder.
• plank_thickness should be the thickness of the plank that the holder should fit over. This measurement should be as close as possible to the actual size of the plank - but take into account the precision of your printer. Measuring your plank with calipers and adding about 0.5 mm should be a good estimate.
• roll_diameter is the diameter of the kitchen paper roll that you want to hang. The model will adapt automatically to move the roll further back (or forward) so the front of the roll should be about in line with the front of the cabinet. The model includes a ~20% margin, so you don't need to add an extra safety margin.
• roll_hole_diameter influences the size of the actual holding bits. I recommend just leaving as-is, unless you somehow have rolls of kitchen paper with a very small or large hole. If you want to hang something other than a roll of kitchen paper, you might need to change it.
• holder_width is the width of the holder. You could make these as wide or thin as you want, but I think 3 cm is a reasonable value.
• draft_angle is the angle at which the top prong points down. This is done on purpose so the holder grip the plank tightly and generate some friction. Without this, the holder would slide perfectly on and off the plank - which you don't want, because you want your roll to stay in place. You could modify this if needed, higher values will grip more tightly, lower values will be easier to slide around.