How We Rank Filament and Printers

This page explains exactly how products get onto PLA.deals, what a "verified" price means, how price per kilogram is calculated, and how we decide whether a filament suits a printer. If a rule is not written here, we do not apply it.

Which products are listed

The catalogue is curated, not scraped. Candidate products come from searches of the retailer's catalogue, and a person reviews each one before it is listed. A product is listed only when we can identify exactly what it is.

Filament must be PLA or a PLA blend sold as a complete spool, refill or pack. Each listing is tied to one exact variant: brand, product line, PLA type (standard, PLA+, matte, silk, high-speed and so on), color, diameter, net filament weight per spool, number of spools and spool type (plastic, cardboard or refill). Products that are not filament (dryers, dry boxes, spool holders, empty spools, nozzles, build plates, sensors, storage bags) are kept out of filament results. Other materials (PETG, ABS, ASA, TPU, nylon, resin) are excluded from PLA results entirely. Small sample spools of 250g or less are listed as samples and are never treated as a 1kg spool.

Printers must be complete FDM (filament) 3D printers. Replacement parts, hot ends, extruders, build plates, enclosures sold separately, upgrade kits, resin printers, wash and cure stations and laser engravers are not listed as printers. A printer sold as a combo with a multi-material unit and the same printer sold alone are different variants with different prices.

What "verified" means for a price

Prices come from the Amazon Creators API, Amazon's official interface for associates. We refresh every listed offer every six hours. Each price on the site shows the date and time it was last verified.

• A price verified within the last 24 hours is shown as a number, with its timestamp.
• If the last successful check is older than 24 hours, we stop showing the number. You see "Check price at Amazon" instead, with no price and no price per kilogram, until a fresh check succeeds.
• If Amazon reports the product as unavailable, we say "Currently unavailable" and take it out of deal lists. Its product page stays up with its specifications and suitable alternatives.
• A struck-through reference price appears only when Amazon returns one for that offer. We never calculate a discount ourselves.

A price on this site is a snapshot taken at the time shown, not a continuous feed. The price on Amazon at the moment you buy is the one that applies.

How price per kilogram is calculated

Price per kg = the current offer price divided by the total verified net filament weight in kilograms. For a multipack, the weight is the net filament weight of all spools combined, so four 1kg spools for $52.00 come out at $13.00 per kg. Spool and packaging weight are never counted.

We show a price per kg only when the net weight has been verified from the manufacturer or the retailer listing and the price itself is within the 24-hour window. If the weight is unknown, there is no price per kg, rather than an estimate. Sample spools show a price per kg for information, but they never appear in "cheapest per kg" rankings, because a 250g spool is not a like-for-like alternative to a kilogram.

Prices are never converted between currencies.

Where specifications come from

Every specification shows its source and the date it was checked:

• Verified against manufacturer documentation: taken from the brand's own product page, data sheet or press material.
• Verified against the user manual: taken from the printer or filament manual.
• As stated in the retailer listing: taken from the retailer's product data. We accept this only for basic facts such as net weight, diameter, color, pack count, build volume and dimensions.
• Not verified: we could not confirm the value, so we do not show one.

Print and bed temperatures, nozzle requirements, multi-material compatibility statements, spool dimensions, supported materials and hot-end specifications are accepted only from manufacturer documentation or manuals.

How we judge filament and printer compatibility

Each filament and printer pairing gets one of four states:

• Compatible: the requirements have been checked against both the printer's and the filament's documented specifications.
• Compatible with conditions: it works with something extra, such as a hardened nozzle, a spool adapter, respooling a cardboard spool for an automatic material system, or a profile change.
• Not recommended: a documented incompatibility, such as a 2.85mm filament on a 1.75mm printer, or an abrasive filled PLA on a printer that only offers a brass nozzle.
• Not verified: there is not enough reliable information. This is the default.

We never mark a filament compatible just because both products say 1.75mm. Each state comes from a written rule that cites the specification it relies on and links to its source.

How results are ordered

By default, deal lists put first the products that are:

1. in stock,
2. verified within the last 24 hours,
3. complete in their key specifications,

and then order them by price per kg for filament and by price for printers. You can re-sort by lowest price, lowest price per kg or brand. The filament finder applies your choices as hard limits first (PLA only, the type, quantity and budget you asked for) and then explains in a few short factual lines why each result matches. If nothing matches, it tells you which choice is limiting the results rather than quietly showing something else.

What never affects ranking

• Commission rates. We do not know or use them when ordering results.
• Payment from brands. There is no paid placement on PLA.deals.
• Ratings or reviews. We do not publish or use star ratings.

Questions about a ranking, or a product you think is classified wrongly? Use the contact page. Fixes are logged on the corrections page.