Printing open chain at 85% flow works the best.
PLA, 200c, 60c bed, 0.12mm layer, 1.2mm wall/shell, 100% cooling, Retraction on, 85% Flow rate
Those numbers vary from printer to printer and it also depends on which PLA filament you use.
I’m surprised you had to decrease flow rate so significantly.
@Johan_Jakobsson true, but in general increasing the wall and reducing the flow gave me the best results.
I have 7 printers and I’ve tested with 4 different filament manufacturers.
@Adam_Steinmark I tested at 95, 90, & 85. All worked good, however 85 gave me this flexibility result.
I’ll post chains from other printers.
I wonder how much it costs to make, compared to buying nylon chain off the shelf?
@Mike_Thornbury but the matching colour is more important 
I can buy a lot of colours, but yeah - if you ‘need’ the right colour, it is worth it, I guess 
@Mike_Thornbury I doubt more than a couple $ of PLA for these. I’ll check what Cura indicates for the amount used to print 16 links
@Glen_Beer And the cost of a 3D printer…
@Mike_Thornbury plus maintenance, power, skill, waste etc. I would bet I’ve spent more on coffee and have nothing to show for it