What is an Indelible Pencil?

Mary McMahon
Mary McMahon

An indelible pencil is a pencil with a type of lead which cannot be erased. Classically, indelible pencils are made with silver nitrate, although other materials may be used as well, and sometimes graphite is mixed into the lead for a familiar look and feel. A closely related pencil, the copying pencil, is a form of indelible pencil with an aniline dye embedded in the lead.

Indelible pencils contain lead that cannot be erased.
Indelible pencils contain lead that cannot be erased.

Indelible pencils were introduced in the early 1800s, as an alternative to the cumbersome and sometimes expensive pens of the era. Prior to the introduction of the indelible pencil, documents with any sense of permanence had to be written with fountain or quill pens. Indelible pencils created the desired lasting print, without the associated difficulties; markings made in indelible pencil would stay put if someone tried to erase the document, or if it was dropped into water or a solvent.

Artists may use indelible pencils because they don't smudge.
Artists may use indelible pencils because they don't smudge.

In the mid-1800s, pencil companies expanded on the concept of the indelible pencil to produce the copying pencil. Copying pencils have an interesting characteristic: when exposed to water, the aniline dye dissolves, creating a purple ink. Someone who wanted to be able to produce a copy of a document could write the document out with a copying pencil, and then blot the document with a moist piece of paper, creating a mirror-image copy. Typically, thin paper or tissue was used so that the writing could be read through the paper.

With the rise of the ballpoint pen and other cheap permanent marking alternatives, indelible pencils are not as common as they once were, but they are still available. Some artists like to work with them, for example, because they don't smudge, and they may also be used to mark things which could be damaged or compromised with ink pens. Art supply stores are a good source for indelible pencils, and these pencils can also sometimes be found at hardware stores.

Indelible pencils are typically clearly marked, to avoid confusion. You can also identify an indelible pencil by the fact that it lacks an eraser on the end, as the marks left by these pencils cannot be erased. However, it's a good idea to keep indelible and regular pencils separate, to avoid unfortunate mistakes.

Prior to the use of indelible pencils, permanent papers were written with fountain or quill pens.
Prior to the use of indelible pencils, permanent papers were written with fountain or quill pens.
Mary McMahon
Mary McMahon

Ever since she began contributing to the site several years ago, Mary has embraced the exciting challenge of being a wiseGEEK researcher and writer. Mary has a liberal arts degree from Goddard College and spends her free time reading, cooking, and exploring the great outdoors.

You might also Like

Readers Also Love

Discussion Comments


I used them to trace over a iron on pattern as some of the patterns won't show up good, so I used them by tracing the pattern then ironed on. It is permanent.


I work in prosthetics and orthotics and we use these when casting patients and modifying/labeling plaster casts.

A liner is used when casting for a prostheses. "Landmarks" are marked on this liner, then wrapped with plaster. The indelible pencil transfers onto the cast, allowing for modification later. I can't imagine what could ever replace the indelible pencil in my field.

We need the transferability and the ability to withstand moisture. They're becoming harder to find!


Indelible pencils are very good for marking plaster models. Dental technicians and dentists uses them a lot in olden days. I am not sure what modern pen can replace it.


I wonder if people ever used indelible pencils to go over lines made by a drafting pencil, once the plan was set. That would seem to be a good use, since drafts and blueprints can be smudged or wet. Does anybody know if architects or builders ever did this, or still do this?


I read that some people use indelible pencils for marking plants, especially bulbs and tubers. I suppose this would make sense, though for the life of me I don't know why they wouldn't just mark it with a pen.

Besides, they're so expensive -- I mean, it's not like you see Pentel or Pentech pencils coming in indelible varieties, and even the more classic HB pencil maker doesn't make them.

I would think they're more trouble then they're worth, since besides being expensive, you'd have to keep them in separate pencil pouches from your normal pencils just to make sure you didn't use one by mistake.

Seems to me to be an outdated technology.


What exactly would you use an indelible pencil for today? I saw an indelible Staedtler pencil last time I was at the art store, and really wondered about that. I guess I could understand if you were marking something and you didn't want to use a pen, but wouldn't you be getting the same problem since you wouldn't be able to erase the pencil either?

I'm just rather confused on the whole thing, to be frank.

Post your comments
Forgot password?