<p>The glass will block most of the uv light; but not all. It will depend on the type of light that the resin is sensitive to; in order to determine if it will continue to cure behind a glass window in direct sunlight. Some resins also sensitive to blue light. You will need to look at the material data sheet for the resin to be able to know for sure. Be advised though, that the resin does not stop curing, and will continue to cure slowly over time, just sitting on the desk.</p>

<p><a href="https://www.thoughtco.com/does-glass-block-uv-light-608316" rel="nofollow noreferrer">https://www.thoughtco.com/does-glass-block-uv-light-608316</a>
From the link:</p>

<blockquote>
  <p>Glass that is transparent to visible light absorbs nearly all UVB. This is the wavelength range that can cause a sunburn, so it's true you can't get a sunburn through glass. However, UVA is much closer to the visible spectrum than UVB. About 75% of UVA passes through ordinary glass. UVA leads to skin damage and genetic mutations that can lead to cancer. Glass does not protect you from skin damage from the sun. It affects indoor plants too. Have you ever taken an indoor plant outside and burned its leaves? This happens because the plant was unaccustomed to the higher levels of UVA found outside, compared with inside a sunny window.</p>
</blockquote>

CC BY-SA 4.0
2020-02-29T16:19:58.677Z
additionaly: many windows are also treated with an extra layer that tries to block more UVA. Glassware usually des not have that treatment. Also, [Plexiglas](https://www.plexiglas.com/export/sites/plexiglas/.content/medias/downloads/sheet-docs/plexiglas-optical-and-transmission-characteristics.pdf) can be pretty much considered a block for the curing UV-light too.
Trish
CC BY-SA 4.0
2020-02-29T16:45:08.813Z
Yea, they do. I doubt mine does because that's cheap glass :)
Polycarbonate also blocks UV.
user77232
CC BY-SA 4.0
2020-02-29T16:18:15.153Z
2020-02-29T16:18:15.153Z
user77232
<p>Yes.</p>
<p>I frequently leave models made on a Saturn printer with Elegoo gray resin on a surface in the sun to slow cure them. If properly cleaned their finish is indistinguishable from models rapid cured in a UV chamber.</p>
<p>It should be noted that I only do this with small models that are Table top miniature scale. Large models with lots of shadows, overhands or complicated detailing may not cure evenly.</p>
<p>I usually do this if I have a lot of models to cure and am too lazy to keep cycling them through my cure station.</p>

CC BY-SA 4.0
2022-05-25T18:59:30.457Z
2022-05-25T18:59:30.457Z
Aaargh Zombies
<p>If I set my prints on the window sill (indoors) will the sunlight still be able to cure the resin? The problem with setting them outside is the wind knocking them over.</p>

CC BY-SA 4.0
2020-02-28T17:28:29.560Z
I'm not writing this as an answer because I'm not sure and don't have experience with resin printing, but generally glass does not significantly block UV unless it has special coatings to do so. So it seems like it should work.
R.. GitHub STOP HELPING ICE
CC BY-SA 4.0
2020-02-28T17:37:41.597Z
Most windows have UV filters on them, reducing the effectivity extremely.
Trish
CC BY-SA 4.0
2020-02-28T23:06:20.023Z
I second the comment of @Trish; my glasses have a coating that turns them into sunglasses under UV light (needed for my sensitivity for light). But, this doesn't work in the car, house or at work. Windows block UV light.
0scar
<sla><resin>
Can you cure resin with sunlight through a window?
Vandel212
# Can you cure resin with sunlight through a window?

(Asked by: username_0 on 2020-02-28)

If I set my prints on the window sill (indoors) will the sunlight still be able to cure the resin? The problem with setting them outside is the wind knocking them over.

**Tags:** sla, resin
> **Comments:**
> **username_1**: I'm not writing this as an answer because I'm not sure and don't have experience with resin printing, but generally glass does not significantly block UV unless it has special coatings to do so. So it seems like it should work.  
> **username_2**: Most windows have UV filters on them, reducing the effectivity extremely.  
> **username_3**: I second the comment of @Trish; my glasses have a coating that turns them into sunglasses under UV light (needed for my sensitivity for light). But, this doesn't work in the car, house or at work. Windows block UV light.  

---

## 2 answers

### Answer by username_4 on 2020-02-29. Score: 2 | Accepted answer

The glass will block most of the uv light; but not all. It will depend on the type of light that the resin is sensitive to; in order to determine if it will continue to cure behind a glass window in direct sunlight. Some resins also sensitive to blue light. You will need to look at the material data sheet for the resin to be able to know for sure. Be advised though, that the resin does not stop curing, and will continue to cure slowly over time, just sitting on the desk.

<https://www.thoughtco.com/does-glass-block-uv-light-608316>
From the link:

> Glass that is transparent to visible light absorbs nearly all UVB. This is the wavelength range that can cause a sunburn, so it's true you can't get a sunburn through glass. However, UVA is much closer to the visible spectrum than UVB. About 75% of UVA passes through ordinary glass. UVA leads to skin damage and genetic mutations that can lead to cancer. Glass does not protect you from skin damage from the sun. It affects indoor plants too. Have you ever taken an indoor plant outside and burned its leaves? This happens because the plant was unaccustomed to the higher levels of UVA found outside, compared with inside a sunny window.

> **Comments:**
> **username_2**: additionaly: many windows are also treated with an extra layer that tries to block more UVA. Glassware usually des not have that treatment. Also, [Plexiglas](https://www.plexiglas.com/export/sites/plexiglas/.content/medias/downloads/sheet-docs/plexiglas-optical-and-transmission-characteristics.pdf) can be pretty much considered a block for the curing UV-light too.  
> **username_4**: Yea, they do. I doubt mine does because that's cheap glass :) Polycarbonate also blocks UV.  

---

### Answer by username_5 on 2022-05-25. Score: 1

Yes.

I frequently leave models made on a Saturn printer with Elegoo gray resin on a surface in the sun to slow cure them. If properly cleaned their finish is indistinguishable from models rapid cured in a UV chamber.

It should be noted that I only do this with small models that are Table top miniature scale. Large models with lots of shadows, overhands or complicated detailing may not cure evenly.

I usually do this if I have a lot of models to cure and am too lazy to keep cycling them through my cure station.


---

