Time Capsule Size Revisited – What do I Really Need?

What size time capsule do I want? Is it what I really need?Family Size Time capsules

If you are just beginning your time capsule project, figuring the size of container you need is one of the first things you need to do. Think about the items you wish to place inside for long term storage.

Your Time Capsule Situation

The average time capsule committee finds it difficult to know what size time capsule container they need.

Even when cost is no object, it is difficult to figure the best size at the beginning of a time capsule project. The obvious answer is to wait until you have all your time capsule items before deciding your final time capsule size.

Your actual circumstances dictate your decision about time capsule size, however.

What’s your scenario? A sampling:

  1. You’ve failed to plan and you need a time capsule — any time capsule — asap.
  2. The mayor’s wife decided she needs one the size of a desk (no one knows why)
  3. You’ve opened a cornerstone and wish to replace one in the same place – the biggest size you can have is 9 in. x 12 in. x 2 in. (or 4 in. x 6 in. x 8 in.)
  4. The time capsule project is private, no one knows what will go inside, and the ceremony is next week.
  5. The time capsule project is public, widely publicized, people from all over can bring things to put inside, and you need to show them the container first.

Reasons abound for taking your best guess as to the best time capsule size for you and your group. Let’s discuss some practical things to consider for sizing and archival storage success.

Most popular time capsule items

Even the most unique time capsules contain documents and letter sized sheets of paper. In the USA a letter sized sheet of paper measures 8-1/2 in. x 11 in. in size. If you have one sheet of paper, that approximates 8-1/2 in. x 11 in. x .002 in. While minuscule, that 3rd dimension becomes important when you add many more to it for a book or a bundle of essays, for example.

The same thinking applies to printed photographs, another popular item for time capsules. You may wish to allow for extra thickness for photos such as the archival fold locking sleeves (fit them back to back, 2 to a sleeve).

But in any case, we are not talking about a vault to accommodate most time capsule project contents. Over 90% of all time capsule projects use a time capsule size of less than 16x16x24 inches.

Time Capsule Size Details

Let’s take an example of the 10 in. x 8 in. x 18 in. Time Capsule Box “Earth”. One needs to visualize this size as 10 inches x 18 inches which is 8 inches thick. The most popular archival paper envelope to hold paper and photo items is a 9x12 inch size envelope. Let’s use that to help visualize the space.

Let’s say the thickness of the paper items inside this envelope is 1/4 inch. That is about 20 sheets of paper. So you can get 4 such envelopes per inch of thickness. In a 10 x 8 x 18 capsule, you have 8 inches of thickness. In fact you could have 8 inches of 10×18 inch papers. More common is our example of 9×12 inch envelopes. You have 4 envelopes per inch and 8 inches, or room for 30 to 32 envelopes in that example.

Now you can see that you have an extra inch in the 10 inch dimension (envelopes are 9 inches), and an extra 6 inches on top (18 minus 12). This leaves some room for artifacts. Place things such as a T-Shirt signed by senior class members, a small toy or two, some lapel pins, CD and DVD media on top. If you find you need more width, go to a larger size. In a larger size, you could lie the papers down flat. That works great if the items are all similar in size. Magazines and city budgets will fit better lying down.

When fitting items into your time capsule, envelopes work best to figure how best to pack inside. Yes, you can use archival zip lock bags. They help keep items separated inside the time capsule. But do not expect them to do wonders. They do not last long and are not water tight at all. In general, most people are over-confident when it comes to plastic bags. 

Using a Mock-up Box to Aid in Time Capsule Size Determination

A mock-up box is a play box. It’s not real. Some customers will make them out of cardboard boxes of a similar size as the real capsule is intended to be. You can cover them with silver wrapping paper or foil (or white paper). A shipping box is the most common mock-up box. You can easily obtain one at a local supply store that has shipping supplies.

Sometimes people make their mock-up out of wood (like a crate) or with stiff plastic sheet (Lucite or polycarbonate). One school made it out of a laundry detergent box–they covered it in and out with a wrapping paper and put “Time Capsule” on the outside. (That one made the contents smell a lot like soap, though!) Another customer used an empty computer monitor casing!

Keep in mind that your mock-up box is NOT the real time capsule container. It just helps you visualize and work with a time capsule size.

Is the real time capsule box not exciting enough for you? Consider what Disneyland did in 1995. The creative and talented 'Imagineers' at Disney used their own artistic and beautiful mock-up of Sleeping Beauty’s castle. Dubbed the ‘Time Castle’, it was certainly more visually exciting than the real stainless steel box that we provided (and it was a Large BOX, not a barrel, and yes it was placed late at night, with very few people on hand to see).