Recycled Filament rPLA and rPETG: Saves Money and the Planet?

In Monday’s topic this week we looked at filament storage and its life cycle as a long game, where it pays to think about what you’ll be doing with the material years down the road; recycled filament is the logical next step in that line of thinking, because it shifts the question from ‘how do I keep the material good’ to ‘where did it come from in the first place and where is it headed’. Recycled filament, whether as rPLA or rPETG, promises two things at once: a smaller environmental footprint and often a lower price too. The reality, though, is more nuanced than the marketing slogan. This article explains how recycled filament is made, how it differs from virgin material, how it prints, and when it makes sense to reach for it.

What is recycled filament and where does it come from?

Recycled filament is FDM printing filament made from plastic that has already been through some manufacturing or consumer cycle, rather than being produced purely from virgin material. It’s marked with the prefix ‘r’, so rPLA is recycled PLA and rPETG is recycled PETG. The key difference from ordinary filament isn’t in the chemistry of the polymer itself, but in the origin of the raw material.

In practice there are two main sources. Post-industrial (pre-consumer) waste is generated right during production: failed batches, offcuts, surplus material from extrusion. Post-consumer waste is made up of things that have already served an end user, typically PET bottles. Post-industrial material tends to be cleaner and more homogeneous, because the manufacturer knows exactly what’s going into the machine.

A good example of the first approach is Prusament PLA Recycled, which consists of 100% recycled Prusament PLA material generated as waste during their own production. Because different colors are mixed together without adding pigments, each batch has a different shade. Filamentive, in turn, uses homogeneous waste from partner extrusion companies that otherwise make things like fishing line or fencing, and reaches up to a 90% recycled content share.

• Post-industrial (pre-consumer): offcuts and rejects from production, cleaner and more consistent quality
• Post-consumer: PET bottles and other consumer plastic, more variable input
• The ‘r’ prefix marks recycled content: rPLA, rPETG, rABS, rPET

How is recycled filament made?

Making quality recycled filament is more demanding than making virgin material, because the input feedstock is nowhere near as consistent. It starts with careful selection and inspection of the inputs. Filamentive states that all input streams go through homogeneity checks so that incompatible plastics don’t get mixed into a single batch; otherwise the result would suffer from an inconsistent diameter and print defects.

During extrusion the filament is measured by lasers on two axes, and if the diameter strays out of tolerance it triggers an alarm. This makes it possible to hit a diameter tolerance of ±0.05 mm and a minimum roundness of 95%, values comparable to ordinary mid-range virgin filament. Prusament goes even further with rPLA Natural Pigments, down to a manufacturing tolerance of ±0.03 mm.

An interesting layer of sustainability is what physically holds the filament together. Filamentive uses 100% recycled plastic spools and recyclable cardboard packaging, so the savings aren’t just in the polymer itself but across the whole packaging chain. It’s a detail worth watching in an eco-focused product, because an empty spool is otherwise pure waste.

rPLA: properties and print settings

rPLA is the friendliest entry point into recycled materials for beginners, because it prints practically as easily as ordinary PLA. Prusament rPLA is rated as easy to print, hard, with a low tendency to warp, and capable of handling both fine details and large objects.

The settings follow classic PLA. Prusament rPLA Natural Pigments recommends a nozzle at 205 ± 10 °C, a heated bed at 40 to 60 °C, and a surface such as PEI, glass, painter’s tape, or glue stick; no enclosure is needed. The Prusament PLA Recycled 2kg version lists a nozzle at 215 °C and a bed at 50 to 60 °C. Part cooling is recommended at 100% fan, which with PLA allows clean overhangs and bridging.

The smaller environmental footprint comes at the cost of a few minor compromises. rPLA is a bit more brittle and more hygroscopic than ordinary PLA, meaning it’s more prone to absorbing moisture. Heat resistance is low, around 59 °C for Prusament rPLA specifically, so the parts don’t belong in a hot car or near a radiator. Sanding afterward is harder because of the material’s hardness, and wet sanding is recommended so the plastic doesn’t locally melt from friction.

• Nozzle: 205 to 215 °C depending on the specific product
• Bed: 40 to 60 °C, no enclosure required
• Part cooling: 100%
• Weak points: higher brittleness, higher hygroscopicity, heat resistance around 59 °C

rPETG and filament from PET bottles

PETG and its relative PET are among the most logical candidates for recycling, because PET is one of the most widespread consumer plastics; just look at any beverage bottle. Filamentive makes recycled PETG from pellets sourced from local recycling centers and builds on the fact that both polymers, ABS and PET, make excellent filament, yet most filament still comes from virgin sources.

rPETG keeps the main strengths of ordinary PETG: greater toughness and better heat and chemical resistance than PLA, which makes it a better fit for functional parts. It prints a bit worse than PLA, is more prone to stringing, and requires thorough drying, since PETG is a hygroscopic material.

A chapter of its own is filament made at home directly from PET bottles. The open PETmachine project cuts a bottle into a long strip and pulls it through a heated extruder onto a spool. The result has a diameter of 1.75 mm and usually a tolerance within 0.05 mm, provided the temperature and speed are calibrated correctly. The catch is that printing such PET filament requires an all-metal hotend capable of 270 °C, and a dual-drive extruder is recommended.

Does recycled filament save money?

The answer is ‘it depends’. Recycled filament isn’t automatically the cheapest option on the market. Prusament PLA Recycled 2kg costs roughly $39, which works out favorably per kilogram since it’s a two-kilogram spool, but the actual savings versus virgin material depend on the brand, any available sale, and what you’re comparing it against.

The real financial logic of recycled material is indirect. The cheapest gram of filament is the one you never print as a failed attempt. Careful planning of your usage, counting the leftover on the spool, and avoiding unnecessary rejects will save more than the small difference in price per kilogram. This is exactly where the ecological and economic thinking meet: less waste means both lower cost and a smaller footprint.

Calculate your usage and the leftover on the spool for your printer below, so you know how much material you have left and whether you’ll make it through your next project.

Does recycled filament save the planet?

Here it’s important to separate marketing from reality. Words like ‘biodegradable’, ‘sustainable’, and ‘eco-friendly’ get thrown around loosely with PLA, but the truth is more nuanced. PLA is indeed plant-based rather than fossil-based, which gives it a better starting position than most plastics, but in a landfill it takes hundreds of years to break down.

The ‘compostable’ label is misleading too. For PLA to actually break down, it needs an industrial anaerobic digester, of which there are only a handful even in developed countries; in home compost or out in nature, PLA barely decomposes at all. Recycling PLA is technically possible but impractical, because tossing it into ordinary sorted waste can contaminate other streams, such as PET, and ruin them.

Recycled filament tackles this problem from the other end. Instead of relying on the plastic breaking down over time, it gives existing waste a second life and reduces demand for newly extracted raw materials. Prusament had the carbon footprint of its recycled filaments calculated, which is a step in the right direction: the environmental benefit should be measured, not just claimed. Another point in favor of sustainability is that bioplastics otherwise compete for land with food crops.

Pros and cons of recycled filament

Before reaching for recycled material, it’s worth weighing both sides. Recycled material isn’t a worse choice, but it’s a choice with a different profile than virgin filament, and it’s good to know what to watch out for.

• Pro: smaller environmental footprint by making use of existing waste
• Pro: comparable diameter tolerance with quality brands (±0.03 to ±0.05 mm)
• Pro: often more sustainable packaging too, such as recycled spools
• Pro: rPLA prints as easily as ordinary PLA
• Con: rPLA is more brittle and more hygroscopic than virgin PLA
• Con: color inconsistency between batches with pigment-free products
• Con: cost savings aren’t guaranteed, depending on brand and sale
• Con: filament from home recycling places higher demands on the hotend and extruder

When should you choose recycled filament?

rPLA is ideal for aesthetic models, interior decorations, figurines, toys, and quick prototypes, that is, parts where you don’t need high mechanical, chemical, or heat resistance. Prusament rPLA Natural Pigments also offers soft, natural shades thanks to bio-based pigments from the food and pharmaceutical industries, which pair well with wooden furniture, for example.

For functional parts that need to hold up, rPETG is a better fit thanks to its greater toughness and heat resistance. Just expect it to print a notch harder and to need more thorough drying. For color-critical projects, where you need a precise and repeatable shade, the batch-to-batch variability of pigment-free recycled material can be an obstacle; there, go with a product that has a defined color, or with virgin material.

One practical note about hardware: the two-kilogram Prusament PLA Recycled spool doesn’t fit a standard holder, so you’ll need to print a holder for a 2kg spool. A small thing, but better to know it ahead of time than in the middle of your first print.

Recycled filament isn’t a miracle solution, but a reasonable compromise. rPLA prints as easily as ordinary PLA at the cost of slightly higher brittleness and hygroscopicity and heat resistance around 59 °C, while rPETG adds toughness for functional parts. Ecologically it makes sense mainly because it gives existing waste a second life instead of relying on PLA’s questionable compostability. Financially, the biggest payoff is a combination: quality recycled material plus careful usage planning so that as few rejects as possible are produced. Store the material dry, dry it as needed, and go ahead and make recycled material your default choice for aesthetic projects.