After fixing the yellow ink tube, the Epson R380 printer occasionally gave off a horrible clunk as the tubes slapped around inside the frame. This routing seems much quieter and, as you can see from the marks on the tubes, leaves much less free to flop around:
I cut a small collar (to the left of the white block with the red cable tie) to guide the tubing up over the edge of the ink cartridge holder, with a ramp from the upper edge and raised edges to hold the tubes in place, from a block of black closed-cell foam. It seems perfectly happy to do its job without anything other than the tubes holding it in place atop the cartridges.
There’s also a block of foam filling a gap under the printer’s top frame member (along the far left edge of the picture) to cushion the tubes as they whack against the edge.
So far, so good.
I’ve dumped a few more tanks of waste ink down the drain. When this printer eventually gives up, I’ll get a color laser and move on.