Tips for using silk filaments to get metallic shiny models

Silk PLA filaments are a plastic wonder that can provide the visual delight of printing in actual metal. It opens the door to amazing paint-free prints, great for projects like lightsaber kits. Here are some of my tips for making lightsaber parts using silk PLA. 

You should eventually learn about your slicers options in order to find your preferred settings, especially about perimeter walls and seams, layer heights, surface patterns, extrusion modifiers, speed, and supports. I'll go over what I learned here.

My preferred silk silver brand at the moment is Ziro silk silver PLA. It has a nice light gray for a more aluminum look than some darker, more duct-tape gray silks I’ve used in the past. You can get it on Amazon. There are plenty more companies selling silks so be sure to see what else is out there. 

• Layer Heights - Silks look shiniest on the sides of prints printed from 0.15mm to 0.2mm layer heights. Beyond those heights it starts getting duller. Just something to consider. 

• Perimeter Walls (Hide infill) - Silk PLA usually has a slight transparency, so having only 1-2 walls can possibly show infill that looks bad. With silks it's better to increase the wall number to at least 3 to completely hide any infill. Careful not to set it too high or you will use a lot more filament.

• Flow Rate - Silk material shininess is most apparent on the sides of a print. Flat top surfaces can look duller from the lines being too squished and overlapping some. If your top surface has a rough texture where you can feel the lines too much instead of being smooth, you should reduce your extrusion flow rate.

You can do this in your slicer. I found a nice balance at 98% of the regular rate gets me much shinier top surface lines, although it’s never perfect. Results will likely vary so test and adjust as necessary. 

Reducing flow rate can also help overhangs by avoiding excess material buildup at warped edges. 

• Z Seam - Every print suffers from it: the point the extruder moves up to the next layer creating a visible seam as it goes. It's unavoidable, and silks suffer from it just as bad. Slicers have ways to minimize the appearance of these seams by allowing you to set where they are located manually or using built in settings to put them on nearest edges to hide them.

In many cases it’s impossible to hide the seam at all. Take a simple upright cylinder. Being round it would have no sharp edges to hide in along the vertical length. The best you can do is to align the seam to look cleaner and move it to the least prominent side. On lightsabers I put all my seams on the opposite side from the front I’m going to display.

• Speed - For a consistent shine, try slowing down to around 65-80% to give the filament time to cool evenly between layers. Too fast can make the print duller or can cause exaggerated ghosting effects on the finish. A good balance for time efficiency is to slow down only the exterior perimeter walls to around 25mm/s in your slicer settings. 

• Temperature - Find your sweet spot temperature for the silk filament you’re using to get the highest shine. I use 215c first layer then 210c for the rest. Your results may vary. 

• Top Solid Infill Pattern - When printing objects like lightsaber emitters (see photo above), a top/bottom infill pattern called ‘Archimedean Chords’ gives a seamless rotating pattern. When printing certain flat or square objects, you might consider rotating the default rectilinear pattern angle from 45 to 0 or 90 degrees to fill in the surfaces with more of a + pattern than a x pattern. You can simply rotate the model on the bed 45 degrees to accomplish this. 

These are just some of the tips I can remember. I’ll update these guides as new things are learned.