FDM 3D printing (Fused Deposition Modeling – printing with thermoplastic filament) requires the first layers of the printed object to firmly adhere to the print bed. Adhesion to the bed is therefore crucial for printing success – the first layer forms the foundation of the entire printed part . If the first layers do not adhere sufficiently, the model may shift or come loose during printing, which usually means a failed print. Not only is model stability important, but also even cooling of the material; poor adhesion often leads to unwanted deformations.

Warping: a typical deformation caused by insufficient adhesion – the corners of the printed object lift from the bed during cooling and curl upward.

Insufficient adhesion most commonly manifests as warping (curling) – the edges of the print (especially the corners) come loose from the bed due to stress during material cooling. With large surfaces, the model may even become completely detached from the bed, after which it moves freely and the printer may produce a disorganized “ball” of plastic. Deformations of the model base caused by lifting not only worsen its appearance but can also impair the functionality of the part. For these reasons, it is essential to ensure the best possible first-layer adhesion to the bed – only this can prevent curling, detachment and other defects associated with FDM printing.

Most common adhesion problems

There are several common causes why a model does not stay attached to the bed. The most common adhesion problems include:

• Warped or incorrectly leveled bed: If the bed is not calibrated correctly (leveled relative to the nozzle), the distance between the nozzle and the surface varies in different places. A gap that is too large means that the filament will not adhere to the surface at all, while a gap that is too small may “squash” the first layer. Incorrect bed calibration is one of the most common causes of poor adhesion .

• Unsuitable bed temperature: Most materials require a heated bed at a certain temperature – if the bed is cold or insufficiently heated, the filament will not adhere to it and the first layer may peel off. For example, printing ABS without a sufficiently hot bed will usually fail. Conversely, an extremely high bed temperature may cause other problems (e.g. excessive softening and flattening of the first layer). An insufficiently heated bed is a common cause of prints detaching .

• Incorrectly configured first layer: Even with a level bed and the correct temperature, the first layer may fail due to unsuitable print settings. A first-layer height that is too high (or a nozzle–bed gap that is too large) causes the filament not to adhere. Conversely, too small a distance (the nozzle is too close to the bed) causes the filament to accumulate or spread on the bed. Printing the first layer too quickly or insufficient extrusion can also reduce adhesion. Printing the first layer correctly (achieving the so-called “elephant foot” at the edges, but not excessively) is essential – the nozzle height and first-layer speed have a direct impact on adhesion .

• Using an unsuitable bed material for the given filament: Not every print surface works well with all types of filament. For example, a completely smooth glass bed may work well for PLA, but with a material such as ABS, the print may easily warp and detach from it . Some modern surfaces (PEI sheets, textured plates, etc.) provide excellent adhesion for a wide range of filaments, while others (e.g. ordinary aluminum or an unheated bed) need assistance for difficult materials (glue, tapes, raft). It is important to match the bed material to the filament being used – an unsuitable combination may lead to adhesion failure.

• Dirty or worn bed: Adhesion is significantly affected by the cleanliness and condition of the surface. Even a thin film of dust, grease from fingers or residue from old glue can prevent the first layer from adhering properly . Therefore, the bed needs to be cleaned (degreased) and maintained regularly. A bed that has already been mechanically damaged or worn (scratched PEI film, peeling surface of a self-adhesive bed, torn painter’s tape, etc.) may also lose its adhesive properties. If you suspect bed wear , it is advisable to restore or replace its surface .

Methods and technologies for improving adhesion

Fortunately, there are a number of proven procedures and tools for improving adhesion to the bed. The methods described below will help ensure that the first layer always adheres well and minimize the risk of warping or detachment.

Bed calibration (manual vs. automatic)

The foundation is correct bed calibration (leveling) relative to the nozzle. On printers without automatic leveling, this is done manually – usually using the so-called paper test. This means moving the nozzle to the corners of the bed so that a thin sheet of paper can pass between the nozzle and the bed with slight resistance . The bed must be level and at the correct height across its entire surface. Manual calibration is performed by adjusting screws or other leveling mechanisms until the gap is the same at all points.

Modern printers often offer automatic bed calibration (auto-leveling). It uses sensors (inductive, capacitive, optical or mechanical probes such as BLTouch) to measure surface irregularities and automatically adjust the first layers accordingly. If the printer supports it, it is advisable to use fully automatic calibration – it saves time and often ensures more accurate leveling than the human eye. Even with auto-leveling, it is a good idea to check from time to time that the system is working correctly (e.g. that there is no dirt on the sensor) and, if necessary, perform rough manual leveling. Thorough bed calibration is the first step toward perfect adhesion.

Correct first layer (nozzle height, speed, extrusion)

Correct print settings for the first layer are equally important. Ideally, the nozzle deposits the filament at the optimal height – neither too high (the filament would simply be laid down and could be dragged) nor too low (the filament would be spread sideways by pressure and could clog the nozzle or damage the surface) . After bed calibration, it is advisable to perform first-layer calibration (this is offered separately by Prusa printers and others), during which the so-called Z-offset is fine-tuned, i.e. the exact nozzle height for the first layer. The operator watches how a test surface is printed and adjusts the height until the filament lies flat against the bed without gaps, but is not “chewed” by the nozzle.

In addition to nozzle height, filament speed and flow in the first layer also play a role. It is advisable to print the first layer more slowly than the rest of the model (typically ~20 mm/s), so that the extruded material has time to adhere and is not torn away by the nozzle’s inertia. It is also possible to slightly increase the amount of material for the first layer (e.g. to 105–120% of the standard flow), causing the filament to flatten more on the bed and increasing its adhesive surface. However, a balance must be found – printing too slowly unnecessarily extends the print time, while excessive extrusion may cause plastic overflow. A correctly configured first layer should create a continuous, slightly flattened “sheet” of filament that adheres evenly to the bed without gaps or lumps. If the edges of the first layer hold and do not curl anywhere, you have succeeded – this is a sign of good adhesion . Conversely, visible peeling of the edges means that an adjustment is needed (lower the nozzle, increase the bed temperature, etc.).

Bed temperature for different materials

Using a heated bed is one of the most effective ways to increase adhesion. The bed temperature must correspond to the material – too low a temperature leads to insufficient adhesion, while too high a temperature can deform the bottom layers. In general:

• PLA: Recommended bed temperature around 50–60 °C . PLA has a relatively low melting temperature and shrinks little, so it often adheres even without a heated bed; gentle heating (e.g. 60 °C) nevertheless increases adhesion reliability.

• ABS: A material prone to significant shrinkage during cooling – it typically requires a high bed temperature of 90–110 °C . A common value is around 100 °C. For ABS, an enclosed printing environment (enclosure) is also recommended to prevent rapid cooling and warping.

• PETG: Recommended bed temperature approximately 70–85 °C (literature gives a range of ~70–90 °C) . PETG warps less than ABS when cooling, but a higher bed temperature helps the first layer adhere. However, be careful with PEI surfaces – PETG may adhere to them too strongly, so it is sometimes advisable to apply a separating layer (see below).

• TPU (ible filaments): Flexible materials generally adhere very well even to smooth surfaces. The recommended bed temperature is around 50–60 °C (for larger models, up to 70 °C is fine) . However, an excessively hot bed may cause soft TPU to “stick” too much and become difficult to remove – with very ible filaments (TPE), it is sometimes possible to print on a cold bed if the surface is rough.

• Other materials: ASA is very similar to ABS, so heating to 90–110 °C and an enclosed chamber are appropriate. Nylon also requires temperatures around 80–90 °C and often a special surface (e.g. Garolite or PVA-based glue, because it adheres poorly to glass or PEI). Polycarbonate (PC) requires even higher bed temperatures (~110–120 °C) and ideally an enclosed, heated chamber.

It is important to follow the filament manufacturer’s recommendations – the optimal bed temperature is usually stated on the spool or in the material data sheet. When problems occur, you can experiment with the temperature (increase or decrease it by a few °C) to achieve better adhesion. However, let us not forget that the rule of “everything in moderation” applies here too: An extremely overheated bed may cause, for example, an excessively soft bottom layer and the formation of so-called elephant feet (an expanded model base caused by its own heat) . Ideally, keep the bed heated to the recommended temperature for the given filament, which ensures sufficient first-layer adhesion without negative side effects.

Types of beds and their compatibility

The choice of print bed type significantly affects adhesion. There are now several types of surfaces on the market – each has its advantages and is suitable for different purposes . The most commonly used are:

• Glass bed: Classic smooth glass provides a perfectly level and smooth surface. Its advantages include easy cleaning (glass can be washed with water or alcohol) and a smooth, glossy bottom side of the print. The disadvantage is that smooth glass may have adhesion problems with some materials – for example, PLA adheres reasonably well to clean heated glass, but ABS will detach (ABS acetone coating or glue helps). Glass also has no ibility, so removing models relies on thermal contraction (after cooling, the print often pops off by itself) or mechanical leverage. With some filaments (PETG, TPU), caution is required because they may adhere too strongly to glass, and a piece of glass may chip off when removing them. In terms of compatibility: PLA, PETG, ABS – all can be printed on glass, but often with the help of adhesives (PLA/PETG glue stick, ABS acetone coating).

• PEI bed (polyetherimide): A very popular surface in modern printers. It is supplied either as PEI film adhered to the bed, or as a removable ible sheet coated with PEI (smooth or finely textured). PEI offers excellent adhesion for a wide range of filaments – PLA, PETG, ABS, ASA and others adhere to it “like nails” at the correct temperature. At the same time, most materials release by themselves after cooling (making model removal easy). Smooth PEI film leaves a glossy bottom on the model; textured PEI (e.g. a powder-coated sheet) leaves a rougher surface, but often holds even better when hot (greater mechanical anchoring of the filament into the surface structure). For PETG and some ible filaments, it is recommended to apply a separating layer (a thin film of glue) to smooth PEI – their adhesion is too strong and the surface could be damaged during removal . In general, PEI is excellent for PLA, ABS, PETG, ASA, TPU etc.; it simply needs to be kept clean and degreased occasionally (IPA, see maintenance).

• Self-adhesive beds (BuildTak-type films and others): These are thin adhesive films applied to an existing bed. They imitate the properties of specialized surfaces – for example, BuildTak is a temperature-resistant plastic film to which most filaments adhere well. The advantage is that when the surface is damaged, the film can be replaced with a new one for just a few dollars. The disadvantage is that some prints adhere too firmly and the film may be damaged when removing the model. These adhesive surfaces provide good adhesion especially for PLA and PETG, but are also used with ABS. They also include various magnetic beds – in most cases, this is a ible spring steel sheet with a surface coating (PEI, smooth or textured) attached by magnets. Flexible build plates are popular because they can be bent after printing, making it easier to remove the print from them. Magnetic ible sheets can have various surfaces (PEI, PC, Nylon, etc.) – the choice depends on the required adhesion.

• Aluminum build plate (bare aluminum): Some printers have a heated aluminum build plate without any additional surfaces. Aluminum itself is not an ideal adhesion surface – it is usually used in combination with films, tapes or coatings. Its advantage is fast and even heating. In practice, however, printing directly on bare aluminum is rare; it is recommended to cover it with either PEI film, Kapton tape, or another adhesive layer depending on the filament.

Each build plate surface therefore has its own properties and compatibility. Smooth surfaces (glass, smooth PEI) produce a nice bottom surface on the model, but may have adhesion problems with materials prone to warping. Rough surfaces (textured PEI, coarse coatings) generally increase adhesion, as they enlarge the contact area and mechanically anchor the first layer. When choosing a build plate, it is a good idea to consider which materials you print most often and, if necessary, keep several types in stock (e.g. glass for PLA, a textured sheet for PETG, a special surface for Nylon, etc.).

Adhesives and auxiliary products (glue, hairspray, sprays, tapes)

Various auxiliary products applied to the build plate are often used to increase adhesion. Their purpose is either to increase the surface’s “stickiness” or to create a temporary layer that the filament adheres to better. The most common include:

• Glue stick (PVA glue): An ordinary glue stick (PVA-based) is an inexpensive and effective aid. It is applied in a thin layer to the build plate (glass, smooth surface) before printing. It mainly improves the adhesion of PLA and PETG – for PLA, coating the glass with glue is often enough for models to adhere excellently. PVA glue also serves as a separation layer – for example, when printing PETG on smooth PEI, applying a layer of glue is recommended so that the print can then be removed easily without damaging the PEI surface. After printing, the glue can be washed off with water.

• Hairspray: An improvised alternative to glue – hairsprays contain resinous components that create a sticky film when sprayed onto the build plate. A popular example is 3DLac (essentially industrial hairspray in an aerosol), which is applied to a cold build plate and left to dry. Hairsprays work well for PLA, ABS and other materials, especially on glass build plates. The disadvantage is the mess – over time, a thick layer of hairspray may form, which must be dissolved and cleaned, and the aerosol can contaminate the area around the printer.

• Special adhesive sprays and coatings: In addition to hairspray, there are sprays specifically designed for 3D printing. For example, Dimafix and PrintaFix are sprays that adhere when heated but release when cooled. They are particularly suitable for ABS and other demanding filaments – they prevent warping on a hot build plate and release the model after printing. Another option is ABS juice (an acetone solution of ABS): it is applied to the build plate (usually glass) and, after the solvent evaporates, leaves a thin ABS film to which new ABS layers adhere perfectly. Similarly, a mixture of ASA or PC in a solvent can be used as an adhesive coating for these materials.

• Build plate tapes: A traditional method from before heated build plates. The best known is blue painter’s tape – strips are applied to the build plate (glass or aluminum), and PLA adheres very well to it even without heating. After printing, the tape can be removed and replaced if necessary. Kapton tape (heat-resistant polyimide film) was widely used for ABS – it covers the aluminum heatbed, and ABS adheres to Kapton on a build plate at ~110 °C fairly reliably. These tapes are useful if no other surface is available or if you want to protect the build plate. Kapton tape is thin and smooth, leaving a glossy bottom; blue tape is rougher and leaves a matte imprint of the paper texture. The disadvantage of tapes is the work involved in applying them and their limited lifespan (often single-use).

• Other aids: Sometimes ABS glue (a special liquid containing acetone and ABS) is used to coat the build plate instead of ABS juice – the effect is the same. Other separation layers are also available for some surfaces, such as a thin film of oil or dish-soap solution (for very “sticky” surfaces such as PEI when printing PETG/TPU). Also worth mentioning is an aid called “mouse ears” – small additional pads at the corners of the model, designed in the model or configured in the slicer, which function as local mini-brims and increase adhesion at critical points (useful for preventing sharp corners from lifting on ABS).

Overall, the use of adhesive aids (glues, sprays, tapes) is very useful, especially with materials prone to detaching or on smooth build plates. Choosing them correctly can significantly increase the chance of a successful print. However, always remember to clean afterward – glue or hairspray residue must be removed, otherwise it will build up over time and may actually reduce adhesion.

Using Brim and Raft – when and why to use them

Slicers (programs for preparing prints) can generate additional layers around or beneath the model to increase first-layer stability. Two techniques are used most often: brim and raft.

Green parts printed on a raft – a wide, grid-like base beneath the models that ensures maximum adhesion to the build plate and prevents corner warping.

Raft consists of several layers of plastic printed beneath the entire model. It functions as a temporary base: the model’s first layer is printed onto the raft (plastic adheres well to plastic), and the raft itself adheres to the build plate over a large area. A raft typically extends several millimeters beyond the model’s edges, has several thicker bottom layers, and its top surface is denser so that the model sits nicely on it. The advantage of a raft is maximum stability – it is particularly helpful with materials such as ABS, which otherwise warp, and with models having a very small contact area (e.g. narrow columns), which could otherwise easily topple. The raft is torn off after printing; most slicers create an intermediate layer between the raft and the model so it can be removed easily, but the bottom of the model is then usually rougher and needs cleaning. Using a raft makes sense if other methods fail – for example, with a large ABS model in an open printer where even a brim did not help, a raft is often the last line of defense against warping. The disadvantages are additional material consumption and the need to finish the underside of the model.

Brim on the other hand, is not beneath the model, but only around it. A brim is essentially an expanded “skirt” – several contour lines are printed around the first layer, but unlike a skirt, they are connected to the model. This creates a thin rim around the model’s base, thereby increasing its contact area with the build plate. Depending on the settings (number of lines), a brim can be from a few millimeters to several dozen millimeters wide. The advantage of a brim is that it provides additional adhesion at the model’s edges – this is particularly helpful for models with sharp corners or a small base, where the corners would otherwise lift. A brim is easy to snap or cut off after printing and leaves no marks on the model (only occasional small burrs on the edge, which can be cleaned up). Compared to a raft, it uses less material and time and leaves the underside of the model untouched. However, a brim is not as helpful as a raft in extreme cases – it does not compensate for an uneven build plate or protect the entire underside of the model; it only prevents the edges from lifting.

When should you use a brim and when a raft? The general rule is: use the smallest amount of support necessary. In other words, if a brim is sufficient, there is no need for a raft. Brim should be chosen for materials that otherwise adhere well (PLA, PETG) when the model has sharp corners or a small contact area – the brim provides the necessary assurance that the corners will not move. A brim also helps stabilize small separate parts of the model (e.g. feet, thin walls) in the first layer. Raft should be used for materials highly prone to warping (ABS, ASA, some Nylon/PC) or when printing on a problematic surface, or if you suspect the build plate is poorly leveled. A raft is also suitable for large models in an open space, where uneven cooling is a risk – an enclosed chamber is a better solution, but is not always available. In extreme cases, a combination can also be used: a large raft with a model featuring a brim on top, but that is an extreme measure for very difficult conditions.

Long-term maintenance and care of the build plate

In addition to one-time measures, it is important to care for the build plate over the long term. Proper maintenance extends the life of the surface and ensures that even tens or hundreds of hours of printing can proceed without adhesion problems.

Cleaning and removing filament residue

Keeping the build plate clean is essential. After each print (or before the next print), you should remove filament residue from the surface – small strands, drops, or remnants of the brim or raft. If you use glue or spray, wash or clean off the accumulated layers after several prints (with warm water and soap in the case of glue, alcohol or acetone in the case of hairspray/spray, depending on the build plate material). Degreasing the surface before printing significantly improves adhesion – isopropyl alcohol (IPA) is most commonly used to wipe the build plate. IPA removes grease from fingers and other contaminants without damaging common surfaces (glass, PEI). Be careful with some special coatings – for example, “roughening” a PEI surface with fine sandpaper or acetone should only be done according to the manufacturer’s recommendations and with caution. For glass, you can also use window cleaner or denatured alcohol in addition to IPA. It is also important to avoid touching the print surface with bare hands unnecessarily – human skin leaves grease that impairs adhesion. When handling the build plate, it is better to use gloves or hold it by the edges.

After printing, let the build plate cool slightly before removing the model – many materials release on their own as the temperature drops (especially on glass or PEI). If the model is firmly attached, use suitable tools: ideally a plastic scraper or special removable handles. Use a metal spatula carefully at a sharp angle to avoid scratching the surface. Filament residue that becomes baked onto the surface (e.g. small PETG drops on PEI) can be carefully scraped off with a blunt object or cleaned with a solvent (be careful – avoid acetone on plastic surfaces, for example; use it only on glass or PEI according to the manufacturer’s instructions). Regular cleaning and removal of residue will ensure that the build plate is always ready to deliver optimal performance.

Preventing wear and damage

To make your build plate last as long as possible, you need to prevent unnecessary wear. Correct nozzle height adjustment is essential – if the nozzle is too low, it may dig into the surface and cause grooves or permanently damaged areas. After every move or major intervention involving the printer, it is a good idea to check the calibration so that the first layer is not extruded against the surface. Also be careful when removing models: forceful prying with sharp tools can scratch glass or tear off the top layer of the build plate. Always bend ible steel sheets before removing them so that the model releases, rather than prying it off with a knife. Never use a hammer or excessive force on glass – instead, heat the model (with a hairdryer) or put the build plate in the refrigerator to cool it down so that the model releases.

If you use tapes or films, remove them slowly and at a sharp angle so that the adhesive remains on the tape rather than on the build plate, if possible. Clean tape adhesive residue with alcohol. Never leave the build plate dirty for extended periods – dried glue/hairspray layers are difficult to remove later and may burn onto the surface during the next print. With some surfaces (e.g. PEI), it is natural for them to become “scorched” over time – small dots and spots from baked-on plastic. This usually does not affect functionality, but if it occurs, you can lightly sand the surface with very fine sandpaper or a nano sponge (according to the build plate manufacturer’s instructions). Also make sure that dust does not settle on the build plate if you print infrequently – covering the printer with a cloth when it is not in use reduces dust accumulation. Overall, gentle handling (no sharp impacts, scratches, or inappropriate chemicals) will significantly extend the life of the build plate.

Replacing the build plate and its lifespan

The lifespan of a print build plate depends on its type. A glass build plate can essentially last indefinitely unless it cracks or gets chipped – wear is minimal (although it may become scratched by tools over time). PEI film or adhesive surfaces have a limited lifespan: after dozens to hundreds of prints, they may lose their adhesive properties (e.g. through smoothing of the texture) or become mechanically damaged. Fortunately, replacement is not complicated – peel off the old film and apply a new one. With removable ible sheets, you may simply need to buy a new sheet, optionally double-sided (one side smooth, the other textured). Tapes are clearly a disposable or short-term solution – painter’s tape is usually replaced every few prints, while Kapton film generally lasts a little longer, but expect to replace it after dozens of hours of printing or when it is significantly damaged.

A good sign that it is time to replace or renew the print bed is a permanent decline in adhesion despite every effort to clean and calibrate it. If models no longer adhere as they used to and the surface is visibly worn, consider investing in a new print bed or coating. You do not have to buy an entire print bed immediately – often, it is enough to purchase PEI film or an adhesive surface and apply it to the existing bed . This will give you a fresh adhesive surface again. With some printers, you can also upgrade the print bed to a more modern option (e.g. replace glass with a magnetic ible sheet with PEI). Lifespan can be extended by alternating between multiple surfaces – for example, using a different sheet for different materials, so that each one wears less.

Overall, a high-quality print bed (glass, a good PEI sheet) will last a very long time and replacement is only necessary when there is obvious damage or deteriorated performance. Regular maintenance, as already mentioned, will extend its lifespan as much as possible. And if replacement does become necessary, look at it positively – it may be an opportunity to try a different type of print bed and improve your print quality even further.

Conclusion

Summary of the most important points: First-layer adhesion is a fundamental prerequisite for successful 3D printing – if the first layer adheres well, the likelihood of failure drops significantly. To ensure adhesion, it is essential to have a properly calibrated print bed and nozzle height, as well as a suitable print-bed temperature corresponding to the filament used and a clean surface free of contaminants. Using the correct type of print bed (or adhesive film) for the given material, or applying glue or another preparation, can significantly increase adhesion and eliminate problems with detachment. Do not hesitate to use slicer aids such as a brim (for a larger first-layer area) or a raft (for maximum stability) when dealing with a difficult print.

From the perspective of proven practices we recommend:

• Calibration: Before every larger print, check the bed leveling and, if necessary, recalibrate the first layer (so-called live Z).

• Temperature: Follow the recommended print-bed temperatures for the given filament; with materials such as ABS, do not hesitate to use the maximum and, if necessary, enclose the printer in an enclosure.

• Surface: Use a print bed suitable for your materials – e.g. a PEI ible sheet as a universal solution for PLA/PETG/ABS, glass with glue for PLA, etc. Experiment to find which surface gives you the best results.

• Adhesives: Keep a glue stick, or 3Dlac or Kapton tape, on hand. These aids can “save” a print when everything else fails (typically with large ABS models, etc.).

• Brim/Raft: For small or problematic prints, add a brim – it costs nothing and can help keep the model stuck down. Use a raft if you have persistent problems with adhesion or warping.

• Maintenance: Clean the print bed after every print and regularly degrease it with IPA alcohol. Be careful not to scratch it and replace the surface (film, tape) in time when it becomes worn.

By following the principles above, you will ensure that your prints run smoothly from the first layer to the last. You will eliminate nuisances such as warped corners, detached models, or ruined prints after hours of printing. Good adhesion to the print bed means that you can fully focus on fine-tuning the remaining print parameters and pushing the boundaries of what your 3D printer can do. Rest assured that the time devoted to preparing the print bed and first layer will always pay off handsomely in the form of perfect prints without compromises. Good luck and happy printing!