An opportunity to learn about what’s not usually on show, as well as see some things for the first time, is offered by a Warwickshire gallery.

Unlocked! Behind the Scenes at the Art Gallery & Museum is the current exhibition at Leamington Spa’s Art Gallery & Museum.

It is billed as a chance to see items that are rarely displayed, and others that are undergoing conservation work.

It seemed strange then that the first painting you see is The Three Generations by Sarkis Katchadourian, which featured in a recent exhibition of works donated to the gallery by Alderman Holt. It is justified though by its appearance in a book of 1,000 paintings to see “before you die”, and the fact that this means the gallery gets requests to see it. And the painting of three Muslim women in varied looks means it is a highlight of the Leamington collection.

The first item listed in the gallery’s collection was a copy of The Antiquities of Warwickshire by Sir William Dugdale, but the real first item is thought to be a mug commemorating a boxing match in the 1860s, when the collection began. It now amounts to 12,500 items, acquired through a mix of donations and some acquisitions. The most recent acquisition is the stunning Satellite II by Noémie Goudal, a large photographic print combining real and imaginary scenery which is on show in the main gallery.

The exhibition moves on to show ethnographical items from around the world, donated over the years (and no longer accepted as gifts), all rather incongruous and not forming a coherent collection, plus ceramics from different eras and countries.

One fascinating item is a Buddhist text in a long scroll, held together with string and a wooden front to it; but in a mixed eclectic collection like this there’s bound to be something to please all tastes.

The Dancing Bear, a painting by William Lee Hankey (1869-1952), is used as an example of conservation work, with what looks like tissue paper currently stuck to parts of it as an element of the work.

Natural History and Archaeology is seen as an orphaned collection, with no new items being accepted, and featuring both local and national pieces. It includes a lovely book showing a drawing of a Blue Heron and Little Egret.

More up to date there’s a photograph of a work created by former artist-in-residence Gerard Mermoz, taking a damaged old portrait and superimposing a comptometer machine on top of it to create a new work, in his familiar style of bringing two things together to create a third.

One area looks at how things have changed over the years; there’s Simeon Solomon’s 1870 painting of The Sleepers and the One That Watcheth, three people embracing, plus Ralph Nicholas Chubb’s Contemplation, and Reclining Nude, the latter featuring a naked young man painted from behind laying in a field where rabbits gambol, both from the 1920s. They all hint at a love that could not then speak its name.

A well-known image of Leamington graffiti, Avoid Cider, features amongst several photos from a Jeremy Deller and Alan Kane exhibition.

It’s interesting to see what’s in the stores and also slightly disappointing there’s no amazing new surprises – but then if there were it would be a scandal they had been hidden away so long. An enjoyable visit, and interesting to learn more about collecting policy and conservation and storage work.

The exhibition is on until July 15.