One of the most powerful and useful features of Lightroom is its keyword capability. Not only can you create a useful set of keywords but Lightroom allows you to put those keywords into a hierarchical structure. This adds a further level of organization to your keywords. Instead of scrolling through an ever growing list of keywords, you can categorize them in a collapsible structure.
Level 3 is contained within Level 2 which is contained within Level 1. The same kind of structure is shown for Level C, Level B, and Level A. The small triangles to the left of these keywords indicates that these levels are collapsible.
When collapsed your keyword list is easier to scroll through and manage.
While Lightroom gives you this organizational structure, the interface is not the best to work in as you build more complicated keyword lists. If, like me, you need more room to organize your thoughts you can turn to other programs to build keyword lists that Lightroom can use. Another advantage to external keyword list files is the ability to easily import them into new catalogs as needed.
The most basic application you can use to build your keyword lists is a text editor. Here is an example of a basic text file of keywords
Each level in the keyword hierarchy is indicated by a TAB character. So colors is our first level keyword. [warm tones] and [cool tones] are preceded by one TAB character and are second level keywords under colors. The keywords red and orange are preceded by two TAB characters making them third level keywords under [warm tones]. So the structure is visually apparent when you look at the text file. (We'll talk later about what the square brackets mean in relation to keywords.)
Depending on your text editor you may or may not be able to show the TAB characters.
Being able to see the TAB characters can be helpful.
If you have a spreadsheet program like Excel then you can use that to build your keyword lists. Spreadsheets can be easier to use since the row and column layout can be more intuitive and help prevent you from accidentally deleting a TAB character (and promoting a keyword up a level unintentionally).
I find spreadsheets easier to manipulate when adding rows or columns. These programs usually have more powerful search and replace features and better spell checking.
Now that we've built our list we can bring it into Lightroom. Under the Metadata menu in the Library module, choose Import Keywords...
Then find your file in the Finder (Mac) or Explorer (Windows) dialog. Now your keywords are in your catalog ready to be used!
Easy! If you later edit your list in the external program you can reimport the file and Lightroom's keyword list will be updated.
So what about those square brackets we added around cool tones and warm tones? The square brackets tell Lightroom that the keyword they surround is a category. For example, if we tag a photo with the keyword blue our list looks like this.
When we export this image the file will contain the keywords colors and blue but not the category cool tones.
If you decide to include the categories as keywords then you can check the option Write Keywords as Lightroom Hierarchy when you export.
Now the file contains both the keywords and the categories.
The possibilities are many. Keywords are powerful and essential tools. As your collection of images grows over time you will be very happy that you added keywords as you went along. Just imagine trying to find an image of a red bird in a pine tree among 10,000 image files without keywords!