From the Latin word for "patchwork," the cento (or collage poem) is a poetic form made up of lines from poems by other poets. Though poets often borrow lines from other writers and mix them in with their own, a true cento is composed entirely of lines from other sources.
For more info: http://www.poets.org/viewmedia.php/prmMID/5771
Wanting Much (Asean Envelope Sonnet)
I gaze upon your mesmerizing face
and caring open twinkle in your eyes.
Your sweet thin lips and parted gentle sighs
invite me to your private earthly space;
While holding your hand in the evening breeze,
I long for your touch the feeling is strange.
A passionate kiss of love we exchange.
You gaze at my breast, this moment I seize.
A longing to have you deep in my core.
For I never wanted to be alone,
and parts of my body long to be kissed,
Take me, abuse me,I beg you for more.
Your brilliance shines more than you even know
can my guilt ridden heart accept it though?
This is a Cento composed of works by Amera and duana
The opening stanza is from: http://allpoetry.com/poem/750531-Forever_Moment__Italian_Sonnet_-by-duana
The middle two stanzas are from: http://allpoetry.com/poem/3038626-The_Seduction-by-Amera-adult
and the closing couple from: http://allpoetry.com/poem/3007938-Reason_for_Living_-_Part_One_Version_2__English_Sonnet_-by-duana
Hence the poem itself is an envelope structure.