Fan shapes are popular in trellis design because they emphasise the plant's upward aspiration. They can be an enrichment on windowless and other lightly structured surfaces they can be-- individually or in groups. On surfaces near the edge of a wall, they can be placed asymmetrically (see 6060). On highly articulated/structured facades (with windows, cornices, etc.), fan forms can have a disruptive effect; in most cases, climbing aids with only vertical and horizontal lines are preferable because they "absorb" the existing structures and support the overall building design. A diagonal design language is then up to the plants and their instincts, which thus naturally 'blur' the grid of the cable system. Fan shapes are ideal for many plants, except for strong twiners like wisteria. Please refer to the sections on climbing plants and planning for support in choosing a construction size/style (see charts at the bottom of each plant profile).