With two spaces on the esteemed Cork Street, Alan Cristea Gallery is perfectly placed both geographically and in terms of its curatorial content to be at the heart of London's contemporary art scene. With the exhibitions Richard Serra: Trajectory and Linear Abstraction running side-by-side at the beginning of this autumn/winter art season, the strength of these spaces has been proven yet again.

Richard Serra is an artist best known for his sculptural works, pushing design to explore weight and balance relationships. His pieces for Alan Cristea, although etchings rather than the large steel works most associated with him, build on these same themes; the pieces from his Arc of the Curve (2004) series paying obvious attention to beauty of the curving form and dramatic spatial relationships through their full broad sweeping curves. To describe these works in detail is somewhat difficult, as many of them appear at first to be a plain thick black line across white paper. Worryingly bland in description, these works are enigmatic in life, the sculptor in Serra building an interest in process and texture. The works have a so-called "found surface" in which, during the etching process, the texture of an exterior stucco wall was used. Thus forcing the viewer to reflect on outdoor against indoor space, and weather-worn pieces against protected, framed artwork. There is little variation within the show as all fifteen pieces seem quite similar, however through process and variation in line weight, each piece has a draw and an aura of its own.

Next door in Linear Abstraction, line is explored very similarly and yet also in very different ways. Showcasing a variety of prestigious artists, from Serra's own professor, Josef Albers, to renowned British op-artist Bridget Riley. The lines and play with curves and geometric space undeniably ties in with Serra's theoretical stance. Here, though, the artworks focus on personal perception (clearly an topic that Riley's screen printed pieces is very much tied to) and colour theory (Alber's relationship with Bauhaus and its intellectual and physical output) distinguishes the exhibition from Serra's works.

Billed as "examining differing approaches to geometric abstraction", the focus on prints in this exhibition brings new depths to the images contained. Through the repetitive process of printmaking the repetitive nature of the geometric forms contained is further emphasised alongside the precision the medium allows – indeed each piece is precise, beautiful and disorientating. Including ten of the world's most prominent artists and a cross-section of their most intriguing graphic works, this exhibition deserves theoretical reverence and artistic attention.

Spread across Alan Cristea's two spaces, these shows are clearly separate; however through running parallel to each other, absorbing relationships are built. To visit one of these shows is worth it, yet being able to see both together allows for an experience that will never again be replicated.

Richard Serra: Trajectory, at Alan CristeaEllen Stone reviews Richard Serra: Trajectory and Linear Abstraction at Alan Cristea's two gallery spaces.4