Centro de hoja

[1] The horizontal and vertical blank gutters divide the sheet into quadrants of 25 stamps each.

The first centro de hoja were the imperforate Cuban patriots issues of 1926.

[3] Some people classify the Christmas issues of 1960[2] as centros de hoja, but since they have no gutters others call them special format stamps.

A little over half of the regular issues, special delivery and airmail stamps issued between the years 1926 and 1952 were produced with intersecting gutters, giving rise to the collection of centros de hoja.

[3] Some of the "writers and artists" series of 1937 sold fewer that 180 sheets.