They're effective in showing off unique features and wearable style of their products.
Watercolors...
Plus simple pen & inks.
It appears as if they use more than one style, or artist, to do the watercolors.
Client/Artist note: It's hard to maintain the same style when you work on a project in many starts and stops -- your pressure may increase or decrease on the pen over months so it makes a heavier or lighter line, or you are using more or less water in your paint so the opacity changes. Projects that get nipped and tucked too much get watered down way past their original design intention also -- so that the real heart of the inspiration may get lost. However, keeping the style consistently different can be a treat to the eye. It's a matter of not trying to copy - rather, intentionally change up - the style.
