<p>Plastic shrinks when it cools, usually, print come loose when you cool down the build plate. If you print on glass, you could put the plate with print in the refrigerator. </p>

<p>If you can't put the build plate in the refrigerator, wait for the plate to cool; the print part sometimes pops off, if not, prying up a corner with an artist palette knife or a razor blade scraper will be enough to pop the print off. </p>

<p><a href="https://i.sstatic.net/ZALFss.jpg" rel="nofollow noreferrer"><img src="https://i.sstatic.net/ZALFss.jpg" alt="Artist palette knife"></a><a href="https://i.sstatic.net/H89wvs.jpg" rel="nofollow noreferrer"><img src="https://i.sstatic.net/H89wvs.jpg" alt="Razor blade scraper"></a></p>

<p>Note that release agents can be used (from experience), but not what you suggest. E.g. when you print PETG on PEI it almost fuses, to release those prints you can use 3DLAC or any other PVA based spray or glue (which normally would increase the adhesion!) to be used as an intermediate less sticking release layer.</p>

<p>Do note all the questions here of people not getting the filament to stick to the build plate, do not grease up the plate, else you won't have a print to get off!</p>

CC BY-SA 4.0
2018-12-19T19:48:25.020Z
upside down spray dusters (canned air) can be used to cool the glass in-situ, which prevents re-leveling.
dandavis
CC BY-SA 4.0
2018-12-19T20:30:10.083Z
@dandavis When using auto leveling, re-leveling will be automatic, but you are right, if you manually level this may require a re-leveling session.
0scar
CC BY-SA 4.0
2018-12-18T21:49:19.977Z
2018-12-18T21:56:49.880Z
2018-12-18T21:56:49.880Z
0scar
<p>The problem with using a release agent is, you really run the risk of the print not sticking to the bed at all. Sticking to the bed is uber important, because if it's not there, the piece isn't going to come out right. Having it stick to the bed is a good thing (something which I struggled with for a while!!). </p>

<p>I believe what most people do to get the piece unstuck from the bed is to use a putty knife. Wedge the flat part under the piece and twist slightly. Continue doing this around the print until you can get it to release. Your best bet is being careful by going easy with it though. Also, if the print is sticking well to the bed, ensure you're not using a raft. This will make it even more difficult. </p>

CC BY-SA 4.0
2018-12-18T20:19:54.043Z
not a putty knife, a sharpened spatula. However, I have seen woodworking tools used too...
Trish
CC BY-SA 4.0
2018-12-18T20:16:30.320Z
2018-12-18T20:16:30.320Z
Pᴀᴜʟsᴛᴇʀ2
<p>I've just printed my very first part and it did not want to come loose from the build plate, it fact, it just broke instead.</p>

<p>I can heat the bed up again and work it off, but I wondered if a release agent would be better?</p>

<p>I have a silicon release spray (like those use with molds).  Could I spray the base with that before starting printing?</p>

CC BY-SA 4.0
2018-12-18T20:28:53.977Z
no, you want the surface clean and dry and non-greasy. i've had prints fail to stick because of fingerprint smudges before, so spraying something would be even worse.
dandavis
CC BY-SA 4.0
2018-12-19T21:28:35.283Z
It may help to know what type of build plate you are using. Glass, PEI, bare aluminum, or others would have different solutions. I use hairspray on glass, and my prints almost always self-release within a few minutes as it cools. Before that I used blue painter's tape on the aluminum plate which worked well but took more time.
mbmcavoy
CC BY-SA 4.0
2018-12-20T13:06:46.133Z
I would highly recommend getting one of those magnetic flexable built plates, you can get them for around $10 from China. It saves a lot of trouble with sticky prints.
Ezra
CC BY-SA 4.0
2018-12-20T15:02:50.767Z
@Ezra I haven't heard of those.  Have you got a link?  I have read people saying to get a glass plate.
BanksySan
<pla><heated-bed><post-processing>
Silicone spray as a release agent?
BanksySan
# Silicone spray as a release agent?

(Asked by: username_0 on 2018-12-18)

I've just printed my very first part and it did not want to come loose from the build plate, it fact, it just broke instead.

I can heat the bed up again and work it off, but I wondered if a release agent would be better?

I have a silicon release spray (like those use with molds). Could I spray the base with that before starting printing?

**Tags:** pla, heated-bed, post-processing
> **Comments:**
> **username_1**: no, you want the surface clean and dry and non-greasy. i've had prints fail to stick because of fingerprint smudges before, so spraying something would be even worse.  
> **username_2**: It may help to know what type of build plate you are using. Glass, PEI, bare aluminum, or others would have different solutions. I use hairspray on glass, and my prints almost always self-release within a few minutes as it cools. Before that I used blue painter's tape on the aluminum plate which worked well but took more time.  
> **username_3**: I would highly recommend getting one of those magnetic flexable built plates, you can get them for around $10 from China. It saves a lot of trouble with sticky prints.  
> **username_0**: @Ezra I haven't heard of those.  Have you got a link?  I have read people saying to get a glass plate.  

---

## 2 answers

### Answer by username_4 on 2018-12-18. Score: 2

Plastic shrinks when it cools, usually, print come loose when you cool down the build plate. If you print on glass, you could put the plate with print in the refrigerator.

If you can't put the build plate in the refrigerator, wait for the plate to cool; the print part sometimes pops off, if not, prying up a corner with an artist palette knife or a razor blade scraper will be enough to pop the print off.

[![Artist palette knife](https://i.sstatic.net/ZALFss.jpg)](https://i.sstatic.net/ZALFss.jpg)[![Razor blade scraper](https://i.sstatic.net/H89wvs.jpg)](https://i.sstatic.net/H89wvs.jpg)

Note that release agents can be used (from experience), but not what you suggest. E.g. when you print PETG on PEI it almost fuses, to release those prints you can use 3DLAC or any other PVA based spray or glue (which normally would increase the adhesion!) to be used as an intermediate less sticking release layer.

Do note all the questions here of people not getting the filament to stick to the build plate, do not grease up the plate, else you won't have a print to get off!

> **Comments:**
> **username_1**: upside down spray dusters (canned air) can be used to cool the glass in-situ, which prevents re-leveling.  
> **username_4**: @dandavis When using auto leveling, re-leveling will be automatic, but you are right, if you manually level this may require a re-leveling session.  

---

### Answer by username_5 on 2018-12-18. Score: 2

The problem with using a release agent is, you really run the risk of the print not sticking to the bed at all. Sticking to the bed is uber important, because if it's not there, the piece isn't going to come out right. Having it stick to the bed is a good thing (something which I struggled with for a while!!).

I believe what most people do to get the piece unstuck from the bed is to use a putty knife. Wedge the flat part under the piece and twist slightly. Continue doing this around the print until you can get it to release. Your best bet is being careful by going easy with it though. Also, if the print is sticking well to the bed, ensure you're not using a raft. This will make it even more difficult.

> **Comments:**
> **username_6**: not a putty knife, a sharpened spatula. However, I have seen woodworking tools used too...  

---

