A striking example of Yves Klein's Relief Éponges series, featuring natural sea sponges saturated in his signature International Klein Blue pigment.

RE 11 belongs to the series of Relief Éponges (Sponge Reliefs) created by Yves Klein around 1960. This work features the artist's signature International Klein Blue (IKB), a pigment he developed to achieve a specific saturation and matte finish. By suspending the pigment in a synthetic resin, Klein ensured the colour remained uniform across the surface, free from the reflective qualities of traditional oil binders. The composition incorporates natural sea sponges, which are fixed to a board and coated in the same intense blue pigment. These organic forms create a physical relief, casting shadows that shift depending on the light source. The sponges act as both a sculptural element and a surface for the paint, absorbing the colour to create a texture that contrasts with the flat, monochrome background. Klein viewed these sponges as living entities that had absorbed the blue of the sea. By mounting them onto a panel, he transformed them into objects of contemplation. The work avoids representational imagery, focusing instead on the sensory experience of colour and the physical presence of the material. The arrangement of the sponges across the square format suggests a deliberate, yet seemingly random, distribution. This piece reflects the artist's interest in the immaterial and the void, concepts he explored throughout his career. The use of the sponge allows for a dialogue between the natural world and the artificiality of the pigment, creating a tension between the object and the colour that defines it. As a piece of Nouveau Réalisme, it challenges traditional notions of painting by incorporating three-dimensional found objects into the pictorial space, inviting the viewer to engage with the work as a physical encounter rather than a window into a scene.