HackSpace magazine

Make organic looking 3D prints

By Ben Everard. Posted

3D printers can make fantastically detailed parts in shapes that are hard to create using other automatic methods, but hobbyist-level machines can only work with plastic. If you prefer a different look and feel, there is a solution to this. Some filament manufacturers have filaments that are mostly plastic (usually polylactic acid, PLA), but also contain wood dust. This may account for up to 30% of the total volume, so it’s still in the minority, but it’s enough to give it a different look and feel to plastic.

Let’s be honest straight away – no one is going to mistake this for wood, at least not up close. It’s just not that realistic. However, it does have a different feel, texture, and even smell to plastic. The wood gives it a matt appearance, and the slight texture on the surface helps hide the layer lines. It’s somewhere between wood and plastic.

This filament is usually made with PLA and, as such, it can be printed more or less exactly as PLA can be (see box opposite). The one caveat to this is nozzle size. It is possible to print woodfill on a standard 0.4 mm nozzle; however, this is more or less at the edge of its abilities. It will be more prone to clogging – and bear in mind that not all woodfill is the same, and not all printers are the same.

At 0.4 mm, there’s no hiding the layers on this bead – even with woodfill – but a bit of sanding will remove them

We’d recommend switching to a 0.5 mm or 0.6 mm nozzle for woodfill. This will help reduce your chance of clogging significantly and, as a bonus, print much faster. Since layer lines are less visible in woodfill (and people expect some ‘grain’ in the surface of wood anyway), it doesn’t detract too much from the look of the prints.

Woodfill is a little more free-flowing than regular PLA, so can be prone to stringing. You can either fine-tune your retraction settings, or just deal with the stringing in post-processing. For simple models, a quick blast with the heat gun is probably easier than spending a few hours going through stringing tests with different parameters. But, if you’ll be using it a lot, then it might be worth perfecting your settings.

One big thing to bear in mind about woodfill is that it’s significantly weaker than regular PLA. As such, you probably shouldn’t be using it for anything with any structural importance whatsoever. And even with purely decorative things, you might want to consider increasing the number of perimeters, or perhaps the infill density, to make sure it’s strong enough.

We had a slightly blocked nozzle when running this print, but we like the effect

We really like woodfill as it’s a cost-effective way of making your prints look a little less plastic. It comes in a range of different colours and textures, so shop around to get something that appeals to you (many filament manufacturers will send you sample packs, so you can test a few out without committing to buying full kilos).   

One curious feature of woodfill is that it can char slightly at high temperatures, leaving it a different colour. You can utilise this to create a wood grain effect in your print by varying the temperature of your prints. There’s a Python script, that also works as a plug-in for some versions of Cura, available on Thingiverse (thingiverse.com/thing:49276). Obviously, if you’re heating something enough to char it, you really shouldn’t be leaving it running unattended.

How much this changes the appearance of the print depends a lot on the particular filament. On some, it’s no more than a slight tint, while on others, it’s very noticeable.


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