The philatelic ue of the word gutter is the space left between postage stamps which allows them to be separated or perforated. When stamps are printed on large sheets of paper that will be guillotined into smaller sheets along the gutter it will not exist on the finished sheet of stamps. Some sheets are specifically designed where two panes of stamps are separated by a gutter still in the finished sheet and gutters may, or may not, have some printing in the gutter. Since perforation of a particular width of stamps is normal, the gutter between the stamps is often the same size as the postage stamp.
I have always wanted to have gutter pairs in my collection when I was young. Finally I acquired my first gutter pair only recently when I restarted my hobby.
And more recently acquired gutter pairs of these beautiful 1980 Great Britain commemorative stamps.
Maybe some day I’ll get gutter block also in my collection.
My next goal is to acquire Tête-bêche. More about that when I get those in my collection.