What’s the difference between PLA and ABS, and what should I use?

If you’re looking for 3D filament, chances are you’ve seen a lot of PLA and ABS available. These are currently the consumer level 3D printing industries’ two main staples – most people tend to print in one or the other, and usually stick to the material they prefer, or that best suits their requirements. Recently there have been new exciting materials become available; you can read about the other specialist materials here.

So out of ABS and PLA – which should you use? We’ll likely get slated for saying this, but generally if you’re not sure and just want to print regular objects for use around the house, the very short answer is simply: PLA, or Poly Lactic Acid

Rad Reindeer Modular 3D Printed Wine Rack
This is a 'Rad Reindeer' modular wine rack printed in our regular Blue PLA

Why do we say that? Well, PLA filament is generally the easiest to print with – it’s an easy material to work with. It’s long-term biodegradable, made from an all-natural organic material (primarily corn-starch and sugarcane). It smells nice, like softly cooked corn when printing. Our PLA is also easy to sand down if you require post print finishing, and is surprisingly strong compared with many.

However, PLA has a lower melting temperature, and is ultimately not as durable and strong as ABS. So if you’re looking to print something that needs to survive a slightly harsher environment (higher temperatures, greater strength required etc.) then ABS is a harder wearing bet. The down sides with ABS (or Acrylonitrile Butadiene Styrene if want some impressive words to pad out your next presentation at work) are that it gives off a slight plastic smell when printing and requires a heated bed to prevent it from warping. If ABS cools too fast, the lower levels can warp. You want to make sure the ABS cools slowly using a heated bed. Start off at around 100-110C for the heated bed and reduce this a little after the first couple of layers.

Both materials are subject to moisture, which can ruin your prints so you want to ensure you keep your filament in an airtight bag with desiccant – like the ones we supply with each order. PLA can absorb moisture from the air if left out too long and undergo de-polymerization, which can cause the PLA to expand slightly. This will cause issues when printing, so the airtight bag is essential for long term storage.

ABS is a little more forgiving – although it can still absorb moisture, if you find this has happened you can usually dry it out ready for printing. If you try to print with damp ABS, it will come out stringy and often under-extrude. To dry it out, just place it on your heated bed at about 50-70C for a few hours or using any source of hot dry air, like a food dehydrator.

For those of you wanting some hard stats on the two materials, our PLA has a density of 1.24 (g/cc) and our ABS is 1.04 (g/cc) – this means the ABS is approximately 16% lighter for the same volume of PLA. Our ABS is one of the hardest available, at 110 Rockwell rating. Looking for PLA with the same hardness as ABS? We call that our PLA PLUS, and you can get it here.

If you’re looking for something a little more durable, a material that’s fast becoming popular is our PETG. This prints at temperature settings around halfway between PLA and ABS (220-240C with heated bed around 80C) and is extremely durable. It’s also odourless when printing, and prints well even when the ambient temperature of your room is low. You can check out our PETG filament here.

Previous Post