Scale refers to how an item (like a sofa or bedhead) fits within a space (as opposed to proportion, which refers to how different elements of a room relate to one another). So, the first question to consider is whether the design’s size, and the visual space it takes up, make sense in the room? In other words, does its scale suit the scale of the space? Large-scale pattern tends to be appreciated best in a large space where the drama of the design can be seen to full effect.
Be aware that when applying a big pattern to smaller pieces like cushions, you want to be sure the surface where you’re applying the fabric is large enough to take in the full effect of the pattern, otherwise it will feel a little cramped.
It’s also important to remember that, if you’re introducing large-scale pattern, the room will require some ‘negative’ space – an area where there’s nothing going on, allowing the eye to rest, to make it feel comfortable.