Modern exposed back cut string staircase with embedded glass.

Cut string staircases can be described as either "modern" or "traditional".
Modern cut string stairs generally have square-edged treads, and the tread and riser overhang the string and have the same thickness.

58146-Jenkinson:
Similar style of staircase but with black metal balusters and 90mm posts.

40824-Pearson:
Similar style of staircase. However, it features 140mm posts and "shadow" post caps.

On a cut string staircase like this, where the treads & risers overhang the string, they need to be the same thickness.

It's possible to use:

• 22mm treads & risers.
• 32mm treads & risers.
• 44mm treads & risers.

We keep all these materials in stock; the thicker the material, the more expensive the staircase.

Generally, the bigger the space, the thicker the material you'll want to use to achieve a "chunkier" look. Thicker materials can also create more of a statement.

This staircase features two feature treads:

• Tread one is a large curtail (square)
• Tread two is a bullnose (square)

These allow the posts to be set back, creating a feeling of more space on the ground floor.

Given this staircase's square-edged treads and modern aesthetic, it makes sense to use square feature treads.

To make the glass fit seamlessly, we groove the treads and risers suitable for glass, then supply the glass panels, which are "zig-zagged" on the bottom, ready to fit in place. Pieces of the supplied infill are used between the panels to create a gap.

The majority of staircases feature 90x90mm posts. However, in larger spaces, it can be appropriate to use larger posts.
We keep 115x115mm posts in stock and offer these on all staircases. This staircase has 115mm posts and matching 115mm pyramid caps.

"Standard Construction" staircases have structural rigidity from wedges and glue blocks. However, this means the underside of the stairs has to be covered.

"Exposed Back" staircases are held together using screws which go in through the string or tread and are then covered; this means the underside can be left exposed (hence the name). 
This takes longer, so there is an additional cost. Still, it can look effective if the property creates a scenario where exposing the underside would add a feature to the stairs such as this one.