This work Untitled from 1971 forms a pair with inventory no. XX.072 and both are part of a portfolio called Phosphorescences, one of the most singular graphic art portfolios produced in Spain of its time. Published jointly by the Museum of Spanish Abstract Art in Cuenca and the Juana Mordó Gallery in Madrid, the portfolio brings together six silkscreens by José Guerrero accompanied by an unpublished poem by Stanley Kunitz translated by Solita Salinas de Marichalar. The silkscreens were printed in Abel Martín's workshop and Fernando Zóbel himself supervised the design of the case containing them: a box lined in silver fabric that imitates a matchbox, with a strip of black sandpaper on the lower part, designed by Jorge Blassi.

However, the two silkscreens preserved in the collection are an artist's proof (A/P) printed on fabric instead of paper, with the same plate as the general edition but retouched by Guerrero himself. They are, therefore, unique pieces within the edition of 75 numbered copies, 15 artist's proofs and 5 out of commerce.

The figurative pretext that runs through the series is the match. Guerrero arrived at it by chance, during a long flight to Gothenburg in the company of Fernando Zóbel, when he had his pockets full of matches because he had just quit smoking: "I began to fiddle with the matches, taking them from one pocket and putting them in the other. I would place them here, I would place them there and I had the sensation that I had fire in my hands". The matches were nothing more than a point of support, a constructive pretext to explore what interested him: to condense energy and contain the tension that abstract expressionism squandered in brushstrokes.

In this silkscreen, an open matchbox occupies the format almost completely. On the left, a large red field, dense and opaque, contrasts with the column of matches on the right side: yellow sticks topped in black that group together like a guard, like a frieze. In the upper strip other yellow heads appear against a black background, glimpsed as if the box were about to open.