To me the most typical pre-war stamps of France. "Sower" (looks to me like Marianne),left with shaded background, issued from 1903 till 1938.To the right:solid background,issued from 1906 till 1937. There is one more type: solid background,but with ground under the sowers feet.There is only one 10 Centimes stamp of this type from 1906.(Missing in my France beginners-collection.)