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  • Prem Sundaram

What are Index Cards?

Updated: Jan 28, 2022

An index card is a card made of cardstock ( large paper ) cut in a standard format, used in recording or storing discrete data. In the past they served as a card index for quick search of a library catalog. Carl Linnnaeus invented the system in 1760. Today they serve a primary purpose of storing information and are often used for learning as flashcards.

Image of old library index cards
An index card in a library card catalog. This type of cataloging has mostly been supplanted by computerization.

A hand-written American index card. Image courtesy of Wikipedia
A hand-written American index card. Image courtesy of Wikipedia

A Typical Modern Paper Index Card Stack
A Typical Modern Paper Index Card Stack

What are Index Cards used for?

Index cards are used in many different applications and environments; in the home to keep and retrieve recipes and other organization records; within companies to keep presentations, project reports and store contact information, to do lists, quick notes, or used as flash cards. The uses are almost limitless, used by students, writers, project managers and so many more.

These note cards can store many types of information: summaries, paragraphs or quotations. Note cards are commonly used to record only the overall idea for large amounts of material.

There are many ways to use them including:

  1. As a quick and easy way to take notes.

  2. To store recipes, shopping lists, and other organizational information.

  3. For business, it can be used to record presentation notes, project research notes, and contact information.

  4. As a great way to brainstorm ideas.

  5. Used to help with studying for exams when used as flash cards.

  6. Used to track progress on projects, goals, and to-do lists

  7. As a way to rearrange or reorganize information quickly and easily.

  8. A great way to visually represent data or information.

  9. Perfect for carrying around small items of information or in your back pocket ready to capture your ideas or for recording quotes, or for use as visual aids.

  10. To capture title and citation information in academic research, with a first card used to create a card index to reference related entries.

In the past, before the advent of digital ones, paper index cards were the often suggested organization method for researchers. A card index is a catalogue of subjects with references to the cards which provide fuller information about them. A card index provides the ability to search for various topics by subject, author, title, etc.

Plus, they can hold data, and won't run out of battery! They can easily fit into a back pocket - the sizes widely vary from standard size to larger cards. They are convenient methods for recording information or any other data.

When used to catalog organizational data, it is often common to create a card index using a first card. This helps to search the remaining cards. These days, especially with hyperlinked digital cards, the same job is done electronically.

Index Cards are heavily used in academic research, not only for recording information but also for bibliographical citations.

This ability to be used in a virtually infinite number of ways, and for it to be so good at storing small amounts of information, make them so valuable. It's what makes them standard stationery in offices and schools.

Check out our article Organizing with Index Cards to learn more

Elements of a Card

A card usually has the follow areas used:

  • The Title area - usually a single line with a heading

  • The Body area - the rest of the front of the card

  • The Back area - the reverse side of the card to hold more information

  • Date - often added onto the card to show when the card was created

  • Link - if being used to either reference a different card or show where the information was captured from (e.g. a research paper reference)

  • Tag - a color marker to visually flag a card for quicker reference and categorization

Diagram of where to place information on an index card
If you are using an online index cards app like NoteDex you can also use index card templates to give a background to the card.

Who uses Index Cards?

As you can gather from the above, the list of people that use them is quite expansive. This includes, but not limited to:

  • Students

  • Writers

  • Project Managers

  • Researchers

  • Business people

  • Lawyers and other professionals

  • Teachers

  • Lecturers

  • Comedians

  • Speech Writers

  • etc.

What Sizes do Index Cards Come in?

The most commonly used are five by three inches (3 x 5). A further range of sizes is available: 4x6, 6x7, 5x8 and ISO-sized a7 (2.9 x 4). Most cards have lines ruled in one direction and larger 5x8 cards have more information. They also come in a variety of paper thickness. Check out our more detailed article The Ultimate Guide to Index Card Sizes for more in depth information.

Index Cards with Handwriting

One benefit of traditional 3 x 5 cards (and uniquely the NoteDex app) is the ability to write on them using a pen (or digital pen in the case of the NoteDex app). The act of writing activates a special brain-body connection that just typing (on a computer) does not evoke. That why people who are writing an article will typically choose to write their ideas on a series of cards. They find it helpful to write their key words, their outlines, as they prepare to write their document.

image of digital index card with handwriting
Example using NoteDex - you can use a digital stylus to take notes on a card

How do you Create and Print an Index Card?

There are very few easy tools available to create a printable index card on the computer. Usually, people are directed to using Word, Excel PowerPoint or Google Docs and told to set the paper size to 3x5 or 4x6 to print index cards. This is very inconvenient and time consuming. Luckily, NoteDex allows you to create picture-perfect Index Cards, add text either on one side or on the other side, blank or ruled, and from just one card to as many as you like. You can print them off as a PDF and print to your printer. Just make sure to feed your printer with the right size card stock and check if your printer can print on both sides if you are looking to print double sided index cards.

Digital index card with text
Example of an index card created with NoteDex - note how 'realistic' it looks - it even has the red-line of a real paper one!

How Much does it Cost to Print Notecards?

It's relatively inexpensive to print notecards. A packet of notecards will be a couple of dollars. If you are using an index cards app then it will be free to create an unlimited amount of cards to store anything you want.

What are Oxford Brand Shop Index Cards?

Oxford is just a popular brand of card. Their most popular are 3 x 5 and 4 x 6 size ruled index cards. They offer a wide variety of choices - blank, ruled, or colorful.

Oxford Ruled Index Cards 300 pack
Oxford Ruled Index Cards 300 pack

What Colors do Index Cards come in?

They come in all colors! Using different colors is great for organizing and brainstorming.

Image of Colored Index Cards from Amazon
Image of Colored Index Cards from Amazon

What are Ruled Index Cards?

Often referred by the brand name, Oxford, a ruled card has two sides so that it is easier for notes to read. The 3 x 5 inches makes this sized device suitable for study, presentation or list building. The lines are usually in blue or black and separated by about 1 cm tall.

What are Dot Grid Cards used for?

These cards can feature dotted lines which can be arranged either horizontally or vertically for your writing. People often use dot grids for doing drawings.

Dot pattern index cards
Dot pattern index cards

How do you Keep Note Cards together?

It is possible to keep note cards organized and store them together - usually by using an adhesive band. holder or ring. Some people also poke holes in either the top right corner of the cards and use a string to hold them together.

Can you get Vertical cards?

Yes, you can either use a blank card and turn it portrait style, or you can get some dedicated cards, including some pre-printed ones with templates. Some apps also have index card templates over and above ruled index cards to give drawing markers - such as NoteDex Index Card Templates

Where can you buy Index Cards?

There are many sources to buy 3x5 and 4x6 index cards such as your local office supplies store in the office products division such as Staples, Office Depot and others. Your grocery stores or pharmacies will also sell them, such as Sam's Club, Walmart, CVS, Ralphs and similar. You can also buy blank or ruled cards on Amazon.

How are Index Cards used in Schools?

They are used in schools for a variety of reasons - to help students write down ideas, to help to learn to write, and to help study as flashcards. Cards are often used in the classroom for group interaction and cohesiveness.

What is the Index Card Method?

This method of studying will let you feel confident in knowing information on your cards and making them more meaningful and empowering for you to be a 5 stars learner. We recommend reading the page to learn more.

In summary the method is ideal for flash cards:

  1. Write each question or term on the back of an index card (3 x 5 size)

  2. On the front of each card, write an answer or an explanation for the question or term

  3. on the back. Use your notes and text for a reference, but put the answer or explanation in your own words whenever possible.

  4. Shuffle the cards so you can't figure out any answers based on their location in the deck.

  5. Look at the card on the top of the deck:

  • Try to answer the question or explain the term.

  • If you know it, great! Put it on the bottom of the deck.

  • If you don't know it, look at the answer, and put it a few cards down in the deck (so you'll come back to it soon).

  • Proceed through the deck of cards and work hard until you know all of the information.

Are Index Cards good for Studying as Flashcards?

A flashcard (or flash card) is simply a card where both sides are used - one for the question and one for the answer. Hence, they are a popular tool to be used to created flashcards. Using flashcards to store facts and learn new information is regarded as a key tool in student learning. Many people find that index cards are good for studying, and flashcards can significantly increase memory and retention skills.

Anatomy Flashcard created using NoteDex Index Cards App
Anatomy Flashcard created using NoteDex Index Cards App


Index Cards are an infinitely flexible tool and have a long history of being useful for capturing notes, ideas, thoughts and information. They are also used as flashcards for studying. There are many types and they come in all shapes and sizes.

It is not so easy to create and print index cards using traditional apps like Word, PowerPoint, Google Docs or Slides, but apps like NoteDex make it a breeze to capture, organize, print and share cards.

Whether on paper or digital, the Index Card is a tried and tested information management tool that has withstood the test of time, and will continue to do so. As long as we humans are wanting to capture, organize and retrieve information, we will continue to do so using these amazing cards for generations to come.

If you are looking to create an index card, then do the planet a favor, and start using NoteDex to create digital ones! You'll save paper and have an unlimited stack of virtual cards. You will be able to do things on the virtual cards that you can't even do with real ones. We love Index Cards and we hope you do too!

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