In Catch-22 there is following passage (my emphasis):

The unfrosted light bulb overhead was swinging crazily on its loose wire, and the jumbled black shadows kept swirling and bobbing chaotically, so that the entire tent seemed to be reeling.

Why is the light bulb "unfrosted"? I understand the meaning of "unfrost", but I don't understand how a light bulb can be unfrosted. Is this some metaphor?

  • 12
    It means a light bulb without a "frosted" surface, so that the glass bulb is clear and you can see the filament inside. images-na.ssl-images-amazon.com/images/I/…
    – Hot Licks
    Commented Mar 17, 2019 at 18:09
  • 5
    Also, I think you'd almost certainly get sharper shadows in light from an unfrosted bulb. And I'm sure we all agree that "single point light sources + sharp shadows" are far more spooky than diffuse lights and softer shadows. Commented Mar 17, 2019 at 18:18
  • 13
    If you believe you understand the meaning of "unfrost", you might be wrong. "Unfrost" isn't a valid English word. There is a word "defrost" which may be what you were thinking of, but "defrost-ed" doesn't have the same structure as "un-frosted". Commented Mar 17, 2019 at 21:03
  • 5
    @FumbleFingers Where did I say unfrosted isn't a word? Commented Mar 18, 2019 at 13:12
  • 4
    @MarkBeadles: Oops, sorry. I wasn't paying attention. On reflection I suppose there are an awful lot of perfectly natural unXXXed words where you'd struggle to defend to XXX as a valid verb (unwant, unabash, undispute,...). Commented Mar 18, 2019 at 13:31

4 Answers 4


It means the light bulb that is "not frosted". Frosted glass is translucent(semi transparent).

So it refers to a clear(transparent) glass bulb where you can see the filament.


enter image description here

Image from Kyle Surges via Nitpicky Artist

A frosted light bulb (l) is one with a translucent white coating sprayed on the interior surface which diffuses the light. Earlier incandescent bulbs were all made of clear glass, i.e. unfrosted (r). Frosted bulbs came on the American market in the 1920s.

  • 5
    Unfrosted lights also cast "harsher" shadows with sharper edges. Frosted lights produce soft natural shadows more similar to those produced outdoors on a sunny day. Shadow softness is also a subconscious visual cue as to an object's distance, so a hard shadow in a small space creates cognitive dissonance, with at least one signal indicating the environment must be extremely large. These factors contribute to the mood of the scene referenced in the book.
    – MooseBoys
    Commented Mar 18, 2019 at 5:52
  • 1
    I think the frosting is not a spray, but a rough surface on the inside of the glass. Commented Mar 18, 2019 at 12:14
  • 3
    @MartinBonner I'm pretty sure you can clean the frosting right off of a lightbulb from the inside. It's probably far cheaper to just mass produce the clear lightbulbs and then blast some of them with a quick shot of some coating.
    – JMac
    Commented Mar 18, 2019 at 14:13
  • 7
    I have filed a hole in a frosted bulb to fill it with colored water. Can confirm the frosting just washes right out. Also if the filament breaks, you can shake it around and easily "scratch"off the coating.
    – JPhi1618
    Commented Mar 18, 2019 at 15:19
  • 6
    @MartinBonner Originally frosted lightbulbs were etched in an acid bath. Modern ones are (mostly?) coated. See en.wikipedia.org/wiki/Marvin_Pipkin Commented Mar 18, 2019 at 16:29

Whilst we can agree about the literal meaning of frosted and unfrosted, the important part is what the significance would be in this context.

We need to look at the properties of these bulbs. Both lampshades and frosting made the light less harsh by making the shadows more diffuse. A lampshade would have given the most pleasant light, at the cost of (1) the lampshade, and (2) reduced efficiency as some light would be absorbed, leading to higher running costs. A frosted bulb would have had the same two effects, to a lesser extent.

This bulb (which clearly had no shade as it was just on a wire) was therefore the cheapest option, in terms of both capital and running costs. So we get a sense of cheapness.

But we also get a sense of atmosphere, as these moving shadows, caused by the swinging bulb would have been much more noticeable, detailed and distracting from this unshaded, unfrosted bulb. Even a small movement would lead to moving sharp patterns on the wall, that would not occur with a frosted bulb.

Addition in response to comment: since the bulb is in a tent it is quite possible it is battery powered. This would accentuate the power-saving aspect. Further, a low-powered bulb is likely. This would have had a physically smaller filament and made the shadows even sharper. Since everything would be close together, it would be easy to see a lot of detail, even fingers and locks of hair in the moving shadows on the walls of the tent.

  • Note that this light bulb was in a tent - so it may even have been battery powered. Also, in a tent, any wind would cause the bulb to be "swinging crazily on its loose wire".
    – TrevorD
    Commented Mar 17, 2019 at 23:28
  • Thank you, @TrevorD. I have added to my answer in response. Commented Mar 18, 2019 at 21:51

Just another picture to illustrate more on what the other answers say (showing when the bulb is lit)

"Frosted" diffuse the light from the filament to give a more even light, or in the case of more modern bulbs the glowing phosphorescent may be coated on the glass

"Unfrosted" - The glass is transparent, giving it a more vintage appearance

Though this an actually vintage bulb still going (the Centennial Light)!

  • 1
    Welcome to ELU. Please add citations to your photos (even if you took them yourself, the world needs to know that).
    – Andrew Leach
    Commented Mar 20, 2019 at 22:20
  • Is that ok @AndrewLeach ? I'm fairly sure I searched for without copyright but these wikimedia images have more obvious details
    – Wilf
    Commented Mar 21, 2019 at 0:04
  • 1
    It's not a question of copyright infringement (this sort of quoting is almost always fair use); it's simply necessary to give credit to the source. This is in the help pages on every SE site; because ELU frequently brings in external corroboratve quotes, we have a number of Meta questions about it too.
    – Andrew Leach
    Commented Mar 21, 2019 at 7:24

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service and acknowledge you have read our privacy policy.