Uncommon but useful design terms

Some design terms have a useful meaning, but aren’t in common use. Here’s a collection of the terms I’ve come across.


Chrome is a general term for the parts of an interface that frame the content. e.g. the controls in a web browser.

Elegance and extravagance

Something is elegant if it does a lot with a little. Something is extravagant if it does a lot with a lot. Both are about efficiency of use of materials, and both are valid. Both are easy to get wrong.


A greeble is something you add to an artefact to make it look more visually interesting. A greeble does not need to have any apparent function other than to break up what would otherwise be a plain visual appearance.


From Leander Kahney’s biography of Jony Ive:

In design, details like buttons and latches that make a design pop have a name: They’re called ‘jewellery’. In the auto industry, door handles and radiator grilles have the same name and the same effect.

Leading lines

In interior design, leading lines are used to guide the eye to points of interest. These can be literal/visible lines, or implied lines. For example, you might design a room so that the way the shadows fall create edges that guide the eye to the fireplace.


Luminance is generally how bright something appears. Importantly, different colours have different luminance. e.g. yellow is brighter than blue, even at the same technical “brightness” value.

Paper cut problem

Some problems are like paper cuts: one doesn’t do much damage, but a few hundred hurts a lot. Each problem is easy to ignore, but if you wait it‘ll be hard to fix them all.

Marginal gains

The opposite of paper cut problems. Cycling coach Sir Dave Brailsford popularised the idea that improving every area by 1% would add up to noticeable overall improvement.

In interface design, if you make small improvements everywhere, eventually the improvement will be noticeable.


Application posture is a concept described in Cooper’s book About Face. It relates to the different ways that software might be used. How you design an interface depends partly on what posture it is expected to have. e.g. a “sovereign” posture means that the application will often be the main focus of a person, and should be designed to reflect that.


In its unfettered derivation, rigour refers to the quality of being extremely thorough and careful and has positive connotations … The adjective, rigorous, commonly refers to strictly applied or adhered to rules, systems or codes of practice … [An alternative title for this paper could be] ‘the value and role of care and thoroughness for Design Practise’.


Lots of designers use the word “affordance” when they mean “signifier”. A signifier communicates something about an interface. For example, the depth effects added to a button signify that it can be pressed. This term was introduced to interface design by Donald Norman in The Design of Everyday Things.

Thrillers and fillers

In gardening, if you design a plant display, you normally want some “thrillers”, which are plants that grab attention, and “fillers” which provide a good back-drop and take up space. The theory also includes “spillers”, which spill over the sides of the plant pot and make the display feel more natural, but this applies less to interfaces.

Pixel peeping

In photography, pixel peeing is when you zoom in so far that you can see the individual pixels. In photography it’s got negative associations. You shouldn’t get caught up in flaws at such a low level. I think in visual design the opposite might be true.

Modularity penalty

In electronics, if you use modular components you might need e.g. a larger device. One alternative is that you use custom parts, which means you can make the device smaller.

There are similarities in interface design. e.g. if you know exactly what content you design for, the design can suit that content perfectly. If you design for variable or unknown content, your interface might need to be more flexible, which means it might not suit specific content as well as it could.


In film, continuity is what you get when you can’t tell if two shots set in the same time and place were filmed at different times. e.g. if someone’s wearing different shoes from shot to shot, it’s clear that the two shots were filmed at different times.

In interface design, continuity is a quality where a series of related designs all feel related, through good choice of element style, etc. e.g. if you use a similar colour palette across the different designs, they feel like they belong together more.

Surface area

Surface area is a concept from science (e.g. physics and chemistry). It generally describes how much of a material is exposed.

In software the term describes how many design decisions need to be made, e.g. if there are lots of screens to design. Generally, the more surface area, the harder the design will be.

“Looks-like” and “works-like” models

With prototypes of physical products, a “looks-like” model is made to help decide what the final product will look like. A “works-like” model is made to help decide how the final product should work. This separation of visual and interaction design is useful to think about in interface design, as well.

Combinatorial explosion

From mathematics, this describes a situation where, as you increase the number of elements in something, the number of relationships between those elements goes up much faster.

Good interface design is about how you manage the relationships between elements. If you add more elements, you have many more relationships to think about. So more elements means harder design.


From Baldassare Castiglione’s “The Book of the Courtier”, this word refers roughly to an intentional lack of visible effort. Even if you are world-class at something, you want to make it look effortless.

In visual design, this might describe a style which looks simple but hides a lot of effort to get the details exactly right. In interaction design, this might describe an interface which does a lot of work behind the scenes to make things seem easy when they are technically hard.

Structure and surface

From architecture, “structure” is the parts of a building designed to make it stand up. “Surface” is the more expressive parts of a building around the structure that give it a visual identity. Note that the same part could be both structure and surface, e.g. if it has exposed steel beams.

In interface design, “structure” might describe the e.g. interaction design or layout choices. “Surface” might describe expressive visual design choices like rounded corners, colours, and visual sprinkles.


From video games, “juiciness” describes some ways a game reacts to input from the player. This includes e.g. particle effects, wobble effects, fun animation touches, etc. Watch the video Juice it or Lose it to see many examples.

In interface design, this idea is useful if you want to add interactions that feel fun or add personality to an interface.

Fiddle factor

This describes an interface with elements that are fun to play with as the person who uses it. e.g. if a button is fun to press for the sake of it, it has fiddle factor. This is usually because of satisfying animation. This is especially true on mobile because touch screens mean you interact with the “fun” elements more directly.