Double Impression
Genuine
Forgery
Gooding #1F1. Engraved in taille-douce (a type of engraving on copper plates where the design is made up of a series of lines; its use was formerly common for postage stamps) on stout, moderately soft wove paper. 

Exist in shades of yellow ochre to yellow orange. The forgery characteristics are:
All the date numerals as as tall as CORREOS and Y.
The "s" of "Cs" is like the numeral "8".
One or two pearls below the Y are shaped like D.
The letters in FRANCO well spaced, with the letters "NCO" leaning to the left. 
The numeral "5" is well formed and a dot following the numeral.

Bartels #C1.1; Earee First Forgery