What is repeat

To understand what a textile repeat is, first consider what a layout is. When developing a textile design, a layout usually comes first. Layout refers to the arrangement of motifs or objects within a frame of the intended overall design. It often has the feeling or indicates that a repeat is present with motifs that fall partway in the frame and partway out. It is used as a starting point or a building block, for a repeat that comes later.
A layout gives the designer an opportunity to work out what the objective of the print will be. Especially easy in a design program as a textile designer can play with colour, scale, negative and positive space etc. all elements of the design that will be carried through to the repeat stage of the design process. When working on a layout, a designer is yet to worry about motifs matching up at the repeat width and depth, only concerned with developing a balance, cohesive fabric design.
To be reproduced on fabric, a textile design must be developed into one standard unit containing a specific arrangement of motifs. The unit is the repeat tile and is repeated across the width and length of the fabric. The repeat tile may look similar to a design layout, with motifs that fall partway over the edges, yet these motifs will match up to become whole when the tile is repeated.
In a general, a design layout (or croquis) is developed either by hand or digitally before being developed further into a seamless repeat for printing. A seamless repeating tile will have its edges or sides match perfectly (seamlessly) when duplicated to sit flush against each other.
Artwork that does not repeat seamlessly creates “break lines” or visible areas where motifs do not match up or are incomplete. The repeat could be out by only one pixel, and yet when printed, will look like a flaw in the design indicating where the repeat should be.
When printed on fabric, a good seamless repeat will trick the untrained eye to only see a well-balanced and cohesive design appearing to never end. The aim is to have the eye continually move about the design, never coming to rest on a particular area or focal point that distracts from other parts of the design or the overall effect completely.
There a several seamless repeat structures that can be employed when developing the repeat tile such as full drop repeat, half drop repeat, mirror repeat. All require that when a repeat tile duplicated across the width and length of the fabric, have all the motifs in that tile flow on seamlessly.