Note that while there any many different and interesting types of filament, different types of filament have different requirements for printing: know your filament’s characteristics.
For instance, glow-in-the-dark PLA filament is fun for students. But be aware that it is typically: (a) fairly abrasive on the extruder nozzle – be prepared to replace your extruder nozzle if you perform much glow-in-the-dark printing, (b) more expensive than regular PLA, and (c) green and blue glow effects are generally more satisfactory than other colors. Some users recommend that best glow effects result from objects that are fairly hollow but with thicker walls, so consider slicing objects using no (or very little) infill while adding a few more shells than usual; when printing via the Polar Cloud, see settings under “PRINT SETTINGS”, “ADVANCED”, “Fill” and “Quality”.
Similarly, color-changing PLA filament – changing color in response to temperature or, for some brands, in response to UV light – can be fun for students. It also tends to be more expensive than regular PLA, but unlike the glow-in-the-dark PLA, does not tend to be especially abrasive.
Wood filament (PLA infused with wood dust/wood fibers) results in objects with the look and feel of wood. A number of different brands, incorporating different types of woods, are available. Note that it’s moderately difficult to work with (as opposed to plain PLA which is relatively easy): it tends to be more finicky about print temperature (which typically needs to be a bit higher than that for Polar 3D PLA), is subject to some shrinking during printing, and may not adhere as easily as plain PLA.
Conductive PLA is PLA infused with conductive carbon. It allows printing low-voltage electronics. It tends to need to print at a slightly higher temperature than plain PLA, and while it is considered fairly easy to print, and is not reported to be particularly abrasive on the extruder nozzle, it is a little harder to get it to adhere (even to itself); also, it tends to be expensive compared to regular PLA.
Carbon Fiber PLA is PLA mixed with small, chopped carbon fibers. It results in strong objects, much stronger than regular PLA, but is extremely abrasive on the extruder nozzle; expect to have to replace your extruder nozzle after printing only 550g (half a regular spool) of carbon fiber PLA.
Metal PLA is PLA combined with fine metallic power, such as bronze powder, brass powder, copper powder, aluminum powder, or steel powder. Objects 3D printed using metal PLA filament will look and feel as if they were made of metal, can be polished like metal, and will be denser (heavier) than regular plastic objects, hefting more like metal. However, metal PLA is quite abrasive on the extruder nozzle, especially when the incorporated metal is a harder metal than the brass of the extruder nozzle. Metal PLA filament is considered quite a difficult filament to get printing well, so be ready for a challenge!
Soft PLA is PLA mixed with a chemical to make it softer and more flexible, to give a rubbery effect, in contrast to normal PLA which yields fairly brittle results. Soft PLA can be quite useful for some types of objects, but note that it can be more of a challenge to print than regular PLA. Typical recommendations are: pay extra attention to first layer adhesion, print a little slower than for regular PLA (perhaps 20mm/s), print at a slightly higher temperature than regular PLA, and use very little (perhaps zero) retraction. Because of the pitfalls of attempting much retraction when using soft PLA, instead consider using the “Enable Combing” option (under “PRINT SETTINGS”, “ADVANCED”, “Retraction”), if your object’s design is suitable (i.e., no flat top surfaces, and mostly connected layer contours). (Note: While it is quite difficult to successfully use soft PLA on a 3D printer that uses a “bowden tube” to feed filament, note that none of the Polar3D, FlashForge, or DREMEL 3D45 printers have such a “bowden tube” design, so printing soft PLA is feasible on them.)
ABS filament is second only to PLA filament in terms of popularity for general 3D printer use. However, it is not usually recommended for use in the classroom, due to the intense fumes it generates during printing which can be dangerous for those with breathing difficulties; when printing ABS, the 3D printer must be placed in a well-ventilated area, and you must avoid breathing in the fumes when it is in use. Also, ABS shrinks while cooling, so it is very prone to curling, and pulling up from the build plate. Due to ABS’s thermal issues, it prints best on printers that incorporate both a heated build plate (to lessen the temperature differential between the bottom and top of the object while printing) and an enclosure around the print area (to lessen the effect of cooling drafts); neither feature is part of the Polar3D printer. However, by extra attention to issues of adhesion and thermal insulation, it is possible to print ABS on a Polar3D printer: use of Elmer’s Xtreme glue stick on the build plate (to glue down the object even as it attempts to cool and shrink) and adding a tall skirt around the main object (to shield it from drafts) are techniques that can be used.
Nylon filament is not as popular as PLA or ABS, and is of moderate difficulty to print, but if you have a 3D printer that can handle it, it has some interesting features. Nylon filament produces very strong and durable, yet somewhat flexible, results, so it is very suitable for making tools or moving mechanical parts such as hinges or gears. As nylon filament absorbs water, it can be dyed (using fabric dyes); you may dye nylon filament before making an object, or dye a nylon object after it has been printed. The water-absorbing property of nylon filament does mean, however, that nylon filament typically needs to be stored specially to keep it dry and the filament may have a short shelf life; it is one of the more hydroscopic filaments (will absorb water from the air). Indeed, nylon filament may even need to be specially dried out before printing – in particular, if you’ve dyed it – as nylon filament that has been allowed to absorb moisture and still retains that moisture will not print as successfully. With nylon filament, as with ABS, you will need to pay particular attention to ensuring good adhesion to the print bed. Nylon filament must be printed at a relatively high temperature – typically about 260° C, and as it is quite susceptible to shrinking while printing, prints much better on a printer with a heated print chamber (and a heated print bed, while not as necessary, is also helpful). Note that the high print temperature means that nylon filament must be printed using an all-metal extruder – and the extruder must not be coated with any material such as PEEK (polyether ether ketone) or PTFE (polytetrafluoroethylene, e.g., Teflon) that starts breaking down (with noxious fumes) at such print temperatures! Many 3D printers (including Polar3D printers) come standard with extruders that are not suitable for printing nylon; always check the specifications of a printer’s extruder or check with the printer manufacturer before attempting to print nylon filament. However, the DREMEL 3D45 printer comes with an all-metal extruder, and the Polar Cloud provides slicing profiles for printing nylon filament on DREMEL 3D45 printers.
PET (PolyEthylene Terephthalate) filament and PETG (a blend of PET with Glycerol) filament are very versatile, reasonably easy to work with, newer filaments, with PETG being a version better adapted for 3D printing. For ease of printing, PETG is intermediate between PLA and ABS. However, PETG does tend to be more expensive than regular PLA. Note general recommendations to print PET and PETG a little more slowly than some other filaments; when printing through the Polar Cloud, see the “PRINT SETTINGS: BASIC” setting for “Print Speed”. A printer with a heated bed is helpful (though not absolutely necessary) for printing with PET or PETG. PETG is hydroscopic (it will absorb moisture from the air), so it must be stored to prevent absorbing moisture; even a day sitting out in high humidity may result in noticeably poorer quality prints (with stringing, and rough surfaces).
There are many more types of filament, with new kinds continuing to come out. While some types produce fumes requiring ventilation (thus being less suitable for the classroom), or need or benefit from a heated build plate (not a feature of the Polar3D printer), or are distinctly more challenging to use than regular PLA, and exotic types tend to be more expensive, still other types may be of interest to you.
For some further discussion of these and additional filament types, see:
Polar 3D youtube video: WWBD – The Different Types of Filaments