# PLA filament

The microscope design is mainly tested using PLA filament. PLA is the most common 3D printer filament. It is easy to use and has low part shrinkage. 

>i **Good quality dry filament is important**
>i 
>i We have found that the lifetime of the microscope is affected by the quality of the PLA filament, as such we recommend buying high quality filament and storing the filament in a dry sealed container when not printing.

>i **Solid colour filaments are most reliable**
>i 
>i Filament colour should not affect the mechanical properties of the parts. However there are some indications that transparent coloured filaments and silk filaments are slightly more prone to breakages. 

## Alternative filaments
PLA is the best workhorse filament, but it does suffer in very hot and humid environments. We have done some testing in biological incubators (~40 °C  and high humidity) where a PLA microscope was seen to suffer significant distortion in the actuator mechanism. 

PETG filament will also print on most entry level Fused Filament 3D printers. In the same incubator tests as the PLA microscope, microscopes printed using PETG showed no degradation. Function of the microscope does not appear to be affected by changing from PLA to PETG, although side-by-side quantitative comparisons have not been done.  

>!! **Do not use ABS, TPA or other durable or flexible filaments**
>!!
>!! The motion mechanism of the microscope requires the right combination of stiffness and flexibility in different sections of the parts. ABS and other tough filaments will be too stiff. Flexible filaments will leave the main structure too unstable.