Organised since 1964 by the Coastal Galleries, Ex-tempore Piran is one of the oldest competitive art festivals of its kind in Slovenia, running uninterrupted since its start. Initiated by Pavle Zamar Zappa, the concept is simple: participating artists (coming from all over Europe) are given a set amount of time to make paintings and ceramic works that are then judged and awarded by an expert jury. The name itself comes from Latin, ex tempore meaning "on the spur of the moment” or "without preparation".
While initially a painting festival, since 1995 it has been augmented with a simultaneously held ceramics edition, and as of 2003 also by the Genius Loci Lera Workshop, held at the nearby salt-pans at Sečovlje. Other events modelled on Piran's Ex-tempore soon spread around what used to be Yugoslavia and also to Italy and Austria.
The number of painters who submit their works to the festival is regularly over 300 (the participating ceramicists are somewhat less in numbers, around 50) – while a significant part of the participants are professional academic artists, the rest are amateur artists who are eager to offer their works for comparative evaluation. An international jury picks a selection of the submitted works (typically about 1 in 3) to be exhibited at either the Piran City Gallery or at the Monfort Exhibition Space in Portorož. Other exhibition spaces run by the Coastal Galleries are sometimes used as well, such as the Loža Gallery and the Meduza Gallery, both in Koper.
Additional side-events occasionally also take place, like, for example, an exhibition of Ex-Tempore's collection of past winners.
The international jury of the festival bestows awards to works in different categories, the most important among them being the annual grand prix for painting. Past winners include Matej Čepin (2009), Bojan Šumonja (2010), Branko Kolarič (2011), Janko Kastelic (2014) and Nicola Tomasi (2014). Other awards (usually) include the young author purchase prize (meaning that the work is purchased by either the organiser or an outside party), some further major purchase prizes (often involving prominent coastal businesses and the three municipalities), the watercolour prize, prizes for work on paper, and honourable mentions. Upon viewing selected exhibited works, various sponsors and regional hotels award a significant number of additional purchase prizes.
The festival of ceramics also gives the grand prix as well (in 2009 it went to Anja Radović and in 2014 to Mladen Ivančić (HR)), plus a solo exhibition at the Pečarič Gallery (in 2009 it went to Andreja Trkman) and – depending on the year – a set of other prizes.
Grand Prix recipients from the past include Gustav Gnamuš, Živko Marušič, Vladimir Makuc, Andrej Jemec, Zvest Apollonio, Kostja Gatnik, Kiar Meško, Jože Tisnikar, Gani Llalloshi, Majda Skrinar, Uršula Berlot, Joni Zakonjšek, Mauro Stipanov (HR), Bruno Paladin (HR) and Sergej Gligorov.