Philaposte has prepared a four-stamp collector titled “Water Through the Seasons – Autumn” for release on 1 October 2026. The specification was made available through PHILAPOSTEL on 19 August. The issue examines autumn water through atmospheric moisture, dew, mist and rain, using photographs arranged within an illustrated collector format.

All four stamps pay the French domestic Lettre Verte rate for letters up to 20 grams. The complete collector measures 149 by 140 millimetres when closed, while each stamp measures 45 by 37 millimetres. Philaposte gives a production quantity of 5,000 collectors and a selling price of €7.50, making the complete folder rather than an individual loose stamp the principal issued format.

Bruno Ghiringhelli created the graphic design from credited photographs. The outer image is by David Greyo of Naturimages and the inner image by Vincent Damarin of Hemis.fr. The “Mist” stamp uses a photograph by Wouter Pattyn of Naturimages, while “Rain” is credited to Jon Arnold Images of Hemis.fr. The collector is printed by offset.

The subject offers a compact meteorological and seasonal thematic issue. Autumn dew forms when water vapour condenses on cooler surfaces as nights lengthen and temperatures fall. By presenting several forms of water within one folder, the issue can fit collections concerned with weather, climate, nature photography, water resources or the progression of the seasons. The low production figure also makes the intact collector's condition and completeness significant.

Sales are scheduled from 1 October through Le Carré d'Encre in Paris, Philaposte's mail-order service, telephone and email ordering, and La Poste's online shop. The available specification does not identify a separate first-day ceremony or cancellation, and the published visuals are described as preliminary representations whose colours are not contractually definitive.