Set design sketches from a 1904 production of “Le voyage de la mariée,”(opérette en trois actes) staged at the Théâtre des Galeries, Brussels, Belgium. Georges Sauvage (1845-1918), designer and artist with the operetta having been co authored by  Edmond Diet and Justin Clérice. Collections of Gallica BnF.

Set design sketch for Act II, Scene 3 of a production of Edmond Diet and Justin Clérice’s Le voyage de la mariée, an operetta in three parts, staged at the Théâtre des Galeries, in Brussels, Belgium in 1904. Georges Sauvage (1845-1918), designer and artist. Signed on the lower right. Collections of the Gallica bnf.fr/Bibliothèque nationale de France. In the public domain due to age. https://gallica.bnf.fr/services/engine/search/sru?operation=searchRetrieve&version=1.2&collapsing=disabled&rk=171674;4&query=%28gallica%20all%20%22mari%C3%A9e%22%29%20and%20dc.relation%20all%20%22cb443740855%22%20sortby%20dc.title%2Fsort.ascending
Set design sketch for Act II, Scene 1 of a production of Edmond Diet and Justin Clérice’s Le voyage de la mariée, an operetta in three parts, staged at the Théâtre des Galeries, in Brussels, Belgium in 1904. Georges Sauvage (1845-1918), designer and artist. Collections of the Gallica bnf.fr/Bibliothèque nationale de France. In the public domain due to age. https://gallica.bnf.fr/services/engine/search/sru?operation=searchRetrieve&version=1.2&collapsing=disabled&rk=171674;4&query=%28gallica%20all%20%22mari%C3%A9e%22%29%20and%20dc.relation%20all%20%22cb443740855%22%20sortby%20dc.title%2Fsort.ascending
Set design sketch for Act II, Scene 2 of a production of Edmond Diet and Justin Clérice’s Le voyage de la mariée, an operetta in three parts, staged at the Théâtre des Galeries, in Brussels, Belgium in 1904. Georges Sauvage (1845-1918), designer and artist. Collections of the Gallica bnf.fr/Bibliothèque nationale de France. In the public domain due to age. https://gallica.bnf.fr/ark:/12148/btv1b53118363h.r=mari%C3%A9e?rk=85837;2#
Set design sketch for Act II, Scene 8 of a production of Edmond Diet and Justin Clérice’s Le voyage de la mariée, an operetta in three parts, staged at the Théâtre des Galeries, in Brussels, Belgium in 1904. Georges Sauvage (1845-1918), designer and artist. Collections of the Gallica bnf.fr/Bibliothèque nationale de France. In the public domain due to age. https://gallica.bnf.fr/ark:/12148/btv1b53118364z.r=mari%C3%A9e?rk=107296;4#
Set design sketch for Act I, Scene 1 of a production of Edmond Diet and Justin Clérice’s Le voyage de la mariée, an operetta in three parts, staged at the Théâtre des Galeries, in Brussels, Belgium in 1904. Georges Sauvage (1845-1918), designer and artist. Collections of the Gallica bnf.fr/Bibliothèque nationale de France. In the public domain due to age. https://gallica.bnf.fr/ark:/12148/btv1b53118356f.r=mari%C3%A9e?rk=128756;0#
Set design sketch for Act I, Scene 2 of a production of Edmond Diet and Justin Clérice’s Le voyage de la mariée, an operetta in three parts, staged at the Théâtre des Galeries, in Brussels, Belgium in 1904. Georges Sauvage (1845-1918), designer and artist. Collections of the Gallica bnf.fr/Bibliothèque nationale de France. In the public domain due to age. https://gallica.bnf.fr/ark:/12148/btv1b53118357w.r=mari%C3%A9e?rk=150215;2#
Set design sketch for Act II, Scene 1 of a production of Edmond Diet and Justin Clérice’s Le voyage de la mariée, an operetta in three parts, staged at the Théâtre des Galeries, in Brussels, Belgium in 1904. Georges Sauvage (1845-1918), designer and artist. Collections of the Gallica bnf.fr/Bibliothèque nationale de France. In the public domain due to age. https://gallica.bnf.fr/ark:/12148/btv1b53118358b.r=mari%C3%A9e?rk=171674;4#

Set design sketch for Act II, Scene 2 of a production of Edmond Diet and Justin Clérice’s Le voyage de la mariée, an operetta in three parts, staged at the Théâtre des Galeries, in Brussels, Belgium in 1904. Georges Sauvage (1845-1918), designer and artist. Collections of the Gallica bnf.fr/Bibliothèque nationale de France. In the public domain due to age. https://gallica.bnf.fr/ark:/12148/btv1b53118359s.r=mari%C3%A9e?rk=193134;0#

The information with these states that they are engravings but they look like watercolor and pencil/pen and ink which was the standard thing by 1904.