Common Plastics: ABS & PLA

Inside the 3D printing plastic materials family, the most commonly-used materials are ABS and PLA in home type printing. They are both thermoplastics, implying that both can liquefy under heat and solidify again when cooled. At this point, this is important to note that both should not be subject to moisture for long period of times to prevent them from retrograde

Despite commonalities, ABS and PLA have a very major difference: ABS is petroleum-based whereas PLA is made obtained from plants like sugar or corn. Furthermore, the grades of the materials are also important; According to Personal 3D Printing Community, the standard PLA grade is 4043D whereas PA-747 is the standard ABS grade

The table below compares ABS and PLA in terms of different selection criteria.

Criteria ABS PLA
Origin Petroleum Plant
Part accuracy Curling during the first contact with the printing bed; problematic when producing parts with sharp corners; needs heated printing bed. Performs better since it can liquefy more; binds layers better; needs cooling.
Material properties Strong plastic; mild flexibility; dissolves in acetone; tends to bend. Earth-friendly; glossier & more rigid (than ABS); melting point is lower (than ABS); tends to splinter and break.
Smell Burning plastic Sugar/corn
Printing surface requirements Needs polyimide tape Can perform with blue painter's tape (cheaper)
Solvents MEK or acetone More complex and dangerous
Color opaque opaque, translucent or transparent

In terms of a home type printer’s needs, both ABS and PLA can produce accurate parts. However, because of differing material properties; ABS needs a heated printing bed (generally above 100°C) while PLA does not require it. On the other hand, parts produced with PLA need to be cooled down and this is not the case for ABS-based parts.

ABS is a more flexible material than PLA which tends to break rather than bend. Due to these properties, ABS is more suitable to print interlocking or pin-connected pieces. PLA has a glossier look than ABS; an advantage which ABS challenges by being easily dissolved in acetone or methyl ethyl ketone (MEK). ABS-based parts can be bound together by using acetone or the parts can be made shiny with it. PLA, positively, is an earth-friendly material; however, its melting point is significantly lower: If a PLA-based part is left in a car under sun, it would probably retrograde. But, PLA is far less stinky than ABS is.

It is underlined that the materials should be evaluated together with the printing environment’s needs. For example, an ABS-based part is more likely to be cracked or warped. Similarly, if the part printed is weaker than expected, one may try to infill the part density, add shells and changing the speed and the temperature of printing.

The last but not least important point regarding ABS and PLA is the calibration issues of the printer. Some of the printers may allow using both PLA and ABS interchangeably; however, every shift between these two and even different colors of the same material will require the calibration of the printer. The calibration is not very easy to handle, especially for home users and therefore should not be underestimated.

Below we offer you a chart that would allow you easily compare the two materials; with every plus to indicate the advantageous one

Keywords ABS PLA
Printing bed heat   +
Cooling +  
Surface requirement   +
Bonding +  
Smell   +
Damage +  
Environment   +