The 1.75mm Natural colored PLA printed awesomely for me, but I had gotten that plastic combo figured out. I had a terrible time trying to get it to print in 3mm Black PLA.
I've got it all sorted out now it looks like. The black isn't perfect, but it is certainly serviceable.
Holding a black PLA Carabiner done at .3mm layer height. The tray of 4 just got finished printing. I was playing with the Slic3r multiple copies settings.
This is done at 0.05mm layer height in 1.75mm Natural PLA. The layers are so fine you can’t see the individual layers. The layering you see here is actually multiple layers and I think is caused by the temperature going up and down.
PLA is very hard, so to make the Carabiners springy, the designer added this little slot. It can now flex.
This is the 0.05mm layer height about half way done. The layers are so thin that it prints the edges clear. The white center is the ‘infill’ and that captures air, so it turns white.
Two different settings, the right one is .2mm layer height and 3 shells, the left one is .3mm layer height and one shell.