The quality of 3D printing doesn\u2019t depend only on the printer settings or the model. One of the most common but often underestimated factors is the condition of the filament. Most thermoplastics used in FDM printing are hygroscopic, meaning they actively absorb moisture from the air. Even a few days in the open can noticeably worsen a material\u2019s properties.<\/p>\n
When damp filament enters the printer\u2019s hotend, the water turns to steam at high temperatures. This causes micro-explosions inside the nozzle that disrupt the structure of the extruded plastic. The result is poor layer adhesion, brittle parts and unpredictable behaviour during printing. That\u2019s why storing filament properly isn\u2019t just a recommendation but a must for anyone who wants consistently good results.<\/p>\n
Before talking about storage methods, it\u2019s important to learn to recognise damp filament. Here are the main symptoms:<\/p>\n
If you notice these problems but haven\u2019t changed the printer settings, damp filament is most likely the cause. Read more about typical problems in our article on 3D printing mistakes<\/a>.<\/p>\n Not all filaments react to moisture the same way. Here\u2019s a ranking of sensitivity \u2014 from the most hygroscopic to the least:<\/p>\n You can compare the properties of different materials in more detail in our article PLA vs PETG vs TPU<\/a>. And a full overview of the available options is on the 3D printing materials<\/a> page.<\/p>\n The simplest and most affordable method. After use, put the spool in a vacuum bag together with the silica gel (desiccant) sachets that come with most filaments. Use a household vacuum sealer to pump out the air \u2014 and the spool will be reliably protected from moisture for months.<\/p>\n Airtight containers with a sealed lid are a more convenient solution for those who print regularly. Silica gel goes at the bottom of the container and the spools inside. Some models let you feed filament straight from the box into the printer through a special hole, so the material stays protected even during printing.<\/p>\n Specialised devices such as the eSun eBOX, Sunlu FilaDryer or Polymaker PolyBox combine a dry box and a dryer. They hold a set temperature and can be used both for drying and for storage during printing.<\/p>\n If filament has already absorbed moisture, it can be rescued by drying. The key is to stick to the right temperatures so you don\u2019t deform the spool or melt the plastic.<\/p>\n A household oven can be used for drying, but with care. Most ovens have a temperature error of 5\u201315\u00b0C, so always use a thermometer to check. Set the lowest temperature and keep the door slightly open for air circulation. Remember: spools made of ABS or PLA plastic (not to be confused with ABS\/PLA filament) can deform if overheated.<\/p>\n A more reliable option is a dedicated filament dryer or even a food dehydrator. They give precise temperature control and even airflow, which is much more effective than an oven.<\/p>\n For optimal filament storage, the relative humidity (RH) should be:<\/p>\n To monitor humidity, we recommend placing a small digital hygrometer inside the storage container \u2014 so you can react to changing conditions in time.<\/p>\n In professional 3D printing studios, storing materials is a systematic process. Filaments are kept in special dry cabinets with humidity control, where RH is automatically held at 10\u201320%. Before each order, materials are checked and, if needed, dried in industrial dehydrators.<\/p>\n This is one of the reasons parts printed by professional services often look noticeably better than home prints. Controlling material moisture is just one of the many aspects that ensure a consistent result on every order.<\/p>\n Storing filament properly is a simple but critically important habit for every 3D printer owner. Vacuum bags, silica gel, airtight containers and timely drying will help you avoid most print quality problems. Even a small investment in organising storage will pay off in saved material and consistently high-quality parts.<\/p>\nWhich materials are most sensitive to moisture?<\/h2>\n
\n
Ways to store filament<\/h2>\n
Vacuum bags with silica gel<\/h3>\n
Dry boxes<\/h3>\n
Filament dryers<\/h3>\n
How to dry damp filament<\/h2>\n
Recommended drying temperatures<\/h3>\n
\n
Drying in an ordinary oven<\/h3>\n
Specialised dryers<\/h3>\n
Recommended humidity levels<\/h2>\n
\n
Tips for long-term storage<\/h2>\n
\n
How professional services store filament<\/h2>\n
Summary<\/h2>\n