Nozzle & SpoolWhich printer to buy, what it'll really cost, and what to avoid.

Dry-box / vacuum storage — Polymaker PolyBox Edition II

Published · Researched 2026-09-20

Research date: 2026-09-20. Every price and claim is dated; conflicting or unverifiable data is flagged openly. Per standing instruction, social sources (Facebook groups, YouTube, forums) were searched before manufacturer and retailer pages.

Overview

This slot covers the dry-box / vacuum storage category, represented here by the Polymaker PolyBox Edition II — the best-known ready-made passive dry box in the category. No single product dominates this category the way a flagship printer does, so this file covers the PolyBox as the canonical example plus the main alternatives (RepBox, vacuum-bag systems, rigid vacuum containers).

The PolyBox is a passive sealed storage-and-print-from box: it uses silica-gel desiccant and a thermo-hygrometer to keep the air around the spools dry. It does not heat or actively dry already-wet filament. Wet filament must be dried in an active dryer (e.g., a SUNLU S4) before going into the box; the PolyBox then maintains dryness. Do not confuse the PolyBox Edition II (passive box) with Polymaker's newer heated PolyDryer / PolyDryer Box line (active dryers).

History: the original PolyBox launched in September 2017 (3D Printing Industry launch coverage: available worldwide from September 25, 2017, MSRP $69.99 / €69.99; TCT Magazine coverage published September 19, 2017). The Edition II — which added slots in the base and lid for flexible filament routing and reusable desiccant bags — was on the market by February 2020 (Core Electronics forum product thread dated 2020-02-09) and was listed as a Shopify product from June 2020. Its exact announcement date is UNVERIFIED.

2026 status: still stocked by multiple EU/Australian/Canadian retailers; one US listing is stale and unavailable (see Pricing).

Key specs

Spec Value Source / note
Type Passive sealed dry box (no heater, no electronics beyond the hygrometer) Polymaker reseller listings; no heating element ("NO HEAT RESOURCE", retailer copy)
Capacity 2 × 1 kg spools or 1 × 3 kg spool Original launch coverage; all reseller listings
Spool-width limits 2 spools ≤ 52 mm width each, or 1 spool ≤ 120 mm width Retail listing spec table
Supported filament diameters 1.75 mm and 2.85 mm Polymaker manual copy
Filament exits 6 rubber exit holes — three in the base, three on the reversible transparent lid; slots in base and lid allow lid removal without stopping a print Edtechs Australia (Edition II features)
Thermo-hygrometer Built-in battery-powered; humidity 10–99 % (±5 %), 1 % resolution, ~10 s response; temperature −50 to 70 °C (±1 °C); 1 × LR44 battery Retail spec tables (consistent across sources)
Target humidity Maintains humidity below 15 % with fresh desiccant Polymaker product copy
Desiccant 2 × 100 g silica-gel bags, reusable (microwave-rechargeable) Voxel Factory (Canada) listing; Edtechs Australia; original launch coverage
Dimensions 315 × 190 × 310 mm Consistent across listings
Weight 1.15 kg (without desiccant and wires) Retail spec tables
Spool mounting Four bearing-clad steel rods — two spools spin independently (original launch coverage) 3D Printing Industry (2017)
Warranty UNVERIFIED — no official Polymaker warranty terms found for this product One Ubuy aggregator listing advertises "lifetime technical support," which is retailer marketing, not a verifiable Polymaker policy

Desiccant-quantity CONFLICT: multiple reseller listings (Voxel Factory, Edtechs, 3dmart, original launch copy) say 2 × 100 g bags, but one EU retailer (comprise.de) lists 4 × 100 g bags. The 2× figure is far better attested; the 4× figure is likely a retailer error — flagged, not silently chosen.

Filament-guide-tube CONFLICT: the 2017 launch article says 150 cm of filament guide tube is included; a reseller contents list says "Filament guide 150mm x 1". The 150 cm figure is more plausible for feeding a printer; both are flagged.

Pricing

Observation date for all rows: 2026-09-20. Do not convert foreign currencies without a dated exchange source.

Item Price Source Notes
PolyBox Edition II — Amazon US $69.99, free shipping (aggregator snapshot; ~4.0/5 from 175 ratings) Amazon product aggregation via search Crawl date unclear; treat as indicative, not confirmed-current.
PolyBox Edition II — HartSmart (US) $69.99 HartSmart listing Stale: crawl ~305 days old, listed as unavailable.
PolyBox Edition II — Voxel Factory (Canada) C$79.99 (sale), crossed out C$89.99 voxelfactory.com (crawl ~42 days old) Canadian retailer; in stock at crawl time.
PolyBox Edition II — EU €69.95 comprise.de In stock.
PolyBox Edition II — UK £54.98 123-3d.ie Listed for context.
PolyBox Edition II — Australia A$89.95 edtechs.com.au Listed for context.
Original launch MSRP (2017) $69.99 / €69.99 3D Printing Industry; 3dprint.com Listed for context — launch price, not current.

UNVERIFIED: a current US street price from an in-stock US retailer was not found on 2026-09-20; the Amazon aggregator snapshot is undated and the HartSmart listing is stale.

What's included / what's needed

In the box (per reseller contents lists, consistent across sources): PolyBox (base + reversible transparent lid), back and front grid, 4 steel rods + 8 bearings, 6 rubber plugs, thermo-hygrometer, LR44 battery, 2 × 100 g desiccant bags, filament guide tube (length conflict noted above), operation manual.

Needed / not included: replacement or rechargeable desiccant — silica gel saturates and must be dried (microwave-rechargeable per Edtechs) or replaced; a spare LR44 battery eventually; an active filament dryer if your filament is already wet (the PolyBox only maintains dryness, it does not dry). Prusa forum owners stress the same distinction: desiccant prevents further absorption but does not remove moisture already in the filament.

Support reality

  • Official Polymaker warranty terms for the PolyBox: UNVERIFIED. No Polymaker warranty page for this product was found in public search. One Ubuy aggregator listing claims "lifetime technical support" and a full refund "if not performing as expected" — this is retailer marketing, not verifiable Polymaker policy.
  • Spare parts: replacement rubber grommets and tubing are not necessarily stocked — a Core Electronics forum thread (2020-02-09) shows their support directing a customer to contact the manufacturer directly for grommet replacements.
  • Product pages at Voxel Factory (Canada), Core Electronics (Australia), and EU/UK retailers show it as a currently stocked catalog item, suggesting ongoing distribution — but no statement from Polymaker about the Edition II's long-term status was found.

Community verdict

Social pulse: durable, liked for what it is, widely criticized on price-per-part:

  • Prusa forum (user "cwbullet"): owns three PolyBoxes, likes them, notes they are "4-stars on Amazon" — simple and effective at keeping filament dry. This is the clearest named-owner endorsement found.
  • Prusa forum thread on vacuum storage (post dated 2025-09-03): users report vacuum bags eventually leak; dedicated rigid containers (PrintDry) described as sturdier than bags. Same thread: desiccant prevents further moisture absorption but does not remove moisture already in filament — the core limitation of all passive boxes.
  • Retailer reviews: commonly praise maintaining low RH (below 15 %) and print-from convenience; common criticisms: it is "an expensive plastic box" for the money (box + hygrometer + desiccant), and the hygrometer display has a poor viewing angle (shopabunda review feedback).
  • YouTube: a 2024 short from the "Filament Stories" channel reviews the heated PolyDryer/PolyDryer Box combo (different product — do not conflate). Polymaker's original PolyBox launch video exists (embedded in the 2017 launch coverage). 3DPrintScape published a written PolyBox storage-box review (see Sources).
  • Facebook groups (2026-09-20): exact "PolyBox" queries in the "3D Printing" group (~17,000 members) and "3D Printing World" group (~10,000 members) returned 0 posts — low/absent signal in these two sampled groups, not evidence of no discussion anywhere (group search may be limited).
  • Instagram/TikTok: no usable public results surfaced via web search; sentiment on these platforms is not established.

Alternatives in this category

  • RepBox — multi-spool wall/bench-mount dry box: 6 × 1 kg spools or 12 × half-kg spools, individual feeds, wall-mountable. A Tom's Hardware article reported pricing starting at $149 — stale (article is old); current price UNVERIFIED.
  • Vacuum-bag + manual pump systems — cheapest and most compact per spool, but Prusa forum users (Sep 2025) report bags and valves eventually leak or get punctured; fine for storage, awkward for printing-from.
  • Rigid vacuum containers (e.g., PrintDry) — sturdier than bags per Prusa forum discussion, but more expensive per spool.
  • Heated dryers (SUNLU S4, Polymaker PolyDryer) — the correct tool when filament is already wet; pair with a passive box for storage.

Sources consulted

Image notes

  • dry-box-filament-storage-01.jpg — exact Polymaker PolyBox Edition II product shot (reseller CDN via Idealo), 642×618. Shows the box with transparent lid and front thermo-hygrometer.
  • dry-box-filament-storage-02.jpg — exact PolyBox Edition II (Tinkerlab reseller), 1594×1613. Higher-resolution product view.
  • dry-box-filament-storage-03.jpg — exact PolyBox Edition II (3DPrintX reseller), 1536×1024.
  • No silent substitution: one HTTP (insecure) image candidate was rejected in favor of HTTPS sources; all three final images are verified exact-model Edition II shots. None shows the heated PolyDryer — no conflation occurred.
  • All three final images were file-magic verified and ffmpeg decode-checked on 2026-09-20; re-encoded to baseline JPEG.

Open questions / UNVERIFIED

  • Current US street price — Amazon aggregator snapshot is undated; HartSmart listing is stale/unavailable. A fresh US retail price is still needed.
  • Edition II exact launch date — on market by February 2020; exact announcement date UNVERIFIED.
  • Official Polymaker warranty terms for the PolyBox — UNVERIFIED; "lifetime technical support" is a retailer's claim.
  • Desiccant quantity — 2 × 100 g (well attested) vs. 4 × 100 g (one EU retailer). Unresolved.
  • Filament guide tube length — 150 cm (launch article) vs. 150 mm (one reseller). Unresolved.
  • RepBox current pricing and availability — the $149 figure is stale.
  • Spool-width limits — 52 mm / 120 mm figures from one retailer; not cross-verified against the official manual.

Deepening pass (2026-09-20)

Social-source attempts this pass

  • Facebook CLI group-post search ("3D Printing", "3D Printing World"): query searches returned empty datasets — substituted with Prusa3D forum, retailer/editorial reviews (Ubuy, shopabunda), and Polymaker's own manuals (BG/ES/RU/HK mirrors, all current).
  • Threads CLI: no usable dry-box owner signal found (searches returned noise).

New evidence: PolyBox Edition II — recurring practical complaints

  • The manual itself documents the top owner gripe: at the end of a spool, "the filament might get stuck in the PolyBox and the 3d printer can drag the PolyBox" — i.e., a nearly-empty spool can yank the whole box off the shelf mid-print. Recurring enough to be in the caution box of every manual revision: https://3dprintx.bg/wp-content/uploads/operation-manual-polybox-a4-en-.compressed.pdf
  • Seal discipline is the whole game. Manual: "Do not open the PolyBox too frequently and close all the unused rubber plugs to preserve the desiccant." Humidity should drop below 15% within 10–30 min of closing; the built-in hygrometer's minimum readout is 10% — it will never show drier than that, a common source of owner confusion ("why won't it go below 10?"). Above 20% = replace desiccant.
  • Value pushback. Ubuy editorial review (2026): several customers feel "the price doesn't reflect the materials used, describing it as a basic plastic box with a small hygrometer" — useful humidity control (under 10% in high-humidity environments) but premium pricing for commodity hardware.
  • The category has moved on: Polymaker PolyDryer system. A Nov 2025 owner review (via shopabunda) praises the newer two-part approach — a heated Dryer Dock (3 heat settings + timer, settings sticker on the dock) plus stackable Storage Boxes with rollers and center-hole support; you can feed the printer while drying or while sealed in storage. Boxes stack but don't latch together. For buyers in 2026, the PolyDryer line is the current Polymaker answer; the Edition II is the legacy passive box: https://www.shopabunda.com/products/polymaker-polybox-edition-3d-printer-filament-storage-box-filament-holder-spool-holder-keeping-filaments-dry-during-the-printing
  • RepBox / PrintDry lane: PrintDry Filament Dryer Pro 3 listed at Voxel Factory ($99.99) — the active-dryer alternative to passive boxes; RepBox still the spool-capacity alternative for farms (not re-verified this pass).

Price re-verification (2026-09-20)

  • PolyBox Edition II current street price not re-verified this pass (3DJake listing live but price not captured; one US listing still stale/unavailable per earlier pass). Earlier figures stand, flagged. PolyDryer Box (heated, newer) is the price anchor to check next: Voxel Factory lists the PolyDryer at $99.99 (crawl 2026).

Open questions carried forward

  • Long-term (>2 yr) Edition II seal/gasket durability — no owner reports found.
  • PolyDryer Box vs. PolyBox Edition II head-to-head owner comparison — wanted for next pass.
  • No raw-quotes file exists anywhere in this project — all evidence paraphrased.

Deepening pass 3 (2026-09-21)

  • Facebook one-time confirmation: --query "dry box" in the 3D Printing group returned [] on 2026-09-21 — the known --query defect, not evidence of absence. Bounded discovery via groups search --keywords "filament dryer dry box" --role any returned zero groups, so no dedicated community was available to mine.
  • Fresh price signals observed 2026-09-21: PolyBox Edition II — €73.50 (123-3D Ireland, 47-day-old crawl), £54.98 in stock (123-3D UK, 45-day-old crawl), A$89.95 (Phaser FPV AU, 4-day-old crawl). A fresh US in-stock price is still missing (HartSmart's $69.99 listing remains stale/unavailable); earlier US figures stand, flagged as such. The PolyDryer Box (Voxel Factory $99.99, crawl 2026) remains the heated-model price anchor.
  • Gaps carried forward: long-term (>2 yr) Edition II seal/gasket durability still without owner reports; PolyDryer Box vs. PolyBox Edition II head-to-head owner comparison still wanted.
A dry box for filament storage.
A dry box for filament storage.
dry box filament storage — photo 02
dry box filament storage — photo 03

Sources