King Amadeo Stamp

What is it? If it helps, this stamp was next to "Barcelona help" stamps in someone else's album.

That's a neat one. The gentleman on your stamps does look like King Amadeo (see Spain A23 in Scotts, around 1872). Also a note at the beginning of the Spain listings in Scott's notes that Stamps of 1854 to 1882 canceled with three parallel horizontal bars or two thin lines are remainders.
Perhaps your stamp is an essay from the Spanish post office department. Amadeo was King from 1870 to 1873, so it appears his brief reign didn't allow for many stamp issues.
I like it!

**A follow up. A quick google search for 'Spain Stamp Essay' turned up an SCF thread from last year with you exact stamp. Your answer is there (and I was right, by the way .)

Thank you very much, and yes, you were right.
Amadeo I (30 May 1845 – 18 January 1890) was the only King of Spain from the House of Savoy. He was the second son of King Vittorio Emanuele II of Italy and was known for most of his life as the Duke of Aosta, but reigned briefly as King of Spain from 1870 to 1873.