A diptych is any object with two flat plates which are a pair, these are attached at a hinge. For example, the standard notebook and school exercise book of the ancient world was a diptych consisting of a pair of such plates that contained a recessed space filled with wax. Writing was accomplished by scratching the wax surface with a stylus; when the notes were no longer needed, the wax could be heated and smoothed to allow reuse. Ordinary versions had wooden frames, but more luxurious diptychs were crafted with more expensive materials; as an art term a diptych is an artwork consisting of two pieces or panels, that together create a singular art piece these can be attached together or presented adjoining each other. In medieval times, panels were hinged so that they could be closed and the artworks protected. In Late Antiquity, ivory notebook diptychs with covers carved in low relief on the outer faces were a significant art-form: the "consular diptych" was made to celebrate an individual's becoming Roman consul, when they seem to have been made in sets and distributed by the new consul to friends and followers.

Others may have been made to celebrate a wedding, or like the Poet and Muse diptych at Monza commissioned for private use. Some of the most important surviving works of the Late Roman Empire are diptychs, of which some dozens survive, preserved in some instances by being reversed and re-used as book covers; the largest surviving Byzantine ivory panel, is a leaf from a diptych in the Justinian court manner of c. 525–50, which features an archangel. From the Middle Ages many panel paintings took the diptych form, as small portable works for personal use. Although the tryptych form was more common, there were ivory diptychs with religious scenes carved in relief, a form found first in Byzantine art before becoming popular in the Gothic period in the West, where they were produced in Paris; these suited the mobile lives of medieval elites. The ivories tended to have scenes in several registers crowded with small figures; the paintings had single subjects on a panel, the two matching, though by the 15th century one panel might contain a portrait head of the owner or commissioner, with the Virgin or another religious subject on the other side.

The outsides, which received considerable wear from travelling, might have simpler decorative designs, including the coat of arms of the owner. Large altarpieces tended to be made in triptych form, with two outer panels that could be closed across the main central representation, they are one type of the multi-panel forms of painting known as polyptychs. The diptych was a common format in Early Netherlandish painting and depicted subjects ranging from secular portraiture to religious personages and stories. A portrait and a Madonna and Child had a leaf each, it was popular in the 15th and 16th centuries. Painters such as Jan van Eyck, Rogier van der Weyden, Hans Memling and Hugo van der Goes used the form; some modern artists have used the term in the title of works consisting of two paintings never connected, but intended to be hung close together as a pair, such as Andy Warhol’s Marilyn Diptych, a modern pop culture icon. "Diptych" is often used in reference to films or pieces of literature that form a complementary pair.

When taken together, they are viewed as illuminating each other and comprising a distinct work of art from the individual parts. An example is the pair of Alan Ayckbourn plays and Garden, it is in this form. The term refers to official lists of the living and departed that are commemorated by the local church; the living would be inscribed on one wing of the diptych, the departed on the other. The inscribing of a bishop's name in the diptychs means that the local church considers itself to be in communion with him, the removal of a bishop's name would indicate breaking communion with him; the names in the diptychs would be read publicly by the deacon during the Divine Liturgy, by the priest during the Liturgy of Preparation. Diptychs were used to inscribe the names of the saints. Although the wax tablets themselves are no longer used, the term is still used in the Eastern Orthodox Church and Eastern Catholic Churches to describe the contents of the diptychs, with all the same connotations. A face was on the inside of each leaf.

One leaf formed the other a horizontal sundial. The shadow caster, or gnomon was a string between them, calibrated as to how far they should open, as the angle is critical; such a sundial can be adjusted to any latitude by tilting it so its gnomon is parallel to the Earth's axis of rotation. A common error states that if both dials show the same time, the instrument is oriented and faces north. A Diptych made as stated as a combined vertical and horizontal sundial with a string gnomon will show the same time on both dials regardless of orientation; this property of self alignment is only true for diptychs in the case for a combination of an analemmatic and a vertical sundial. A double dial on a flat plate consisting of a horizontal and an analemmatic dial will be aligned properly if both dials show the same time; some diptychs had rough calendars, in the form of pelekinons calibrated to a nodus in the form of a bead or knot on the string. These are accurate to about a week, good enough to time planting of crops.

Wilton Diptych, an rare survival of a late Medieval religious panel painting from England Poly

The Hundred of Campbell is a cadastral hundred of the County of Robinson in South Australia. The main town in the hundred is Maryvale; the traditional owners of the area are the Wirangu and Nauo people, both speakers of the Wirangu language. The first European to sight the area was Dutch explorer Pieter Nuyts, in 1627 in the Gulden Zeepaard, and, in 1802, Matthew Flinders on his voyage in the Investigator. Flinders named the nearby Streaky Bay; the first European land exploration was that of John Hill and Samuel Stephens in 1839, followed by Edward John Eyre in the same year

The Stone Jail Building and Row House are two adjacent stone buildings located on Water Street in Tonopah, Nevada. The jail was built in 1903 and the adjacent row house in 1908. Both building were at one time used as a brothel; the buildings were added to the National Register of Historic Places in 1982. In May 1900 prospector Jim Butler found silver ore in Mount Oddle. Other prospectors followed, a small mining town started to grow at the foot of the hills. By November 1900 this had grown into the town of Tonopah. In 1901 a timber framed jail had been built, at the end of that year the population had risen to between 2,000 and 3,000; the more secure stone jail was built in 1903 to replace the existing timer frame building. The jail was built on Water Street, considered Tonopah's red light district at the time because county commissioner Egan and district attorney Charles L. Richards wished to keep the jail out of the town's more prominent areas; the Nye County seat was moved from Belmont to Tonopah in 1905, the Nye County Courthouse built.

A jail was added to the courthouse in 1907 and the old jail became a private residence. The adjacent row house, was built in 1908 as a brothel and the jail became a brothel around this time; the row house has since been called "one of the best preserved brothels in Tonopah" by a historic survey. The jail was at some time used as a garage; the jail house is a single story building of 20 by 25 feet. It is built of uncut random stone with chink and mortar bonding, under a double pitched corrugated metal roof; the original steel door is no longer in the opening enlarged to take timber garage doors. At the time of listing as a historic place, the window still had the original steel bars in place. A shed roof addition was built in about 1908, but this was removed; the row house is a single story rectangular building built of cut granite. The original sloping asphalt roof was still in place at the time of listing; the building is divided into 3 bays of a single room, each room having its own external door and window.

This is a typical "crib" arrangement for prostitution. The buildings were added to the register on May 20, 1982 as one of a number of buildings in Tonopah added on that date. Others added included Nye County Courthouse, Tonopah Public Library and Tonopah Volunteer Firehouse and Gymnasium