They consisted of wooden statues (usually of knights in armour) into which nails were driven, either iron (black), or coloured silver or gold, in exchange for donations of different amounts.
[2][3] They were promoted as a patriotic fund-raising method in German-speaking parts of the Austro-Hungarian Empire and also in the German Empire, including by publications such as Gotthold Riegelmann's Der Stock in Eisen: praktische Ratschläge zur Errichtung einfacher Nagelholzmale mit Ideenskizzen und Kostenberechnungen (The Stock im Eisen: practical advice on the erection of simple wooden monuments for nailing with sketched ideas and cost calculations)[4] and Benno Fitzke and Paul Matzdorf's Eiserne Kreuz-Nagelungen zum Besten der Kriegshilfe und zur Schaffung von Kriegswahrzeichen (Iron cross nailings for the best benefit of war aid and for the creation of war monuments).
[6] Municipalities and charitable organisations, either specially founded associations or the Red Cross, had a statue or other emblem made out of wood (oak was sometimes recommended), sometimes by well known sculptors, such as the medieval knight Wehrmann in Eisen by Mathieu Molitar on the Naschmarkt in Leipzig.
In York, Pennsylvania, the same fundraising method was used with the opposite meaning: people paid 10 cents to drive a nail into the head of a statue of the kaiser with a red, white and blue handled hammer.
[81][82] Florian Dering, a museologist at the Munich Stadtmuseum, describes a nailing game called Nagelbalken, which became popular after World War I in German-speaking countries and is still used to raise money for charity as well as at weddings, for the newlyweds to display their skills to those present.