Engraving
Attributed to Johannes Wierix, 1572. 

Transcription of Inscription [Lampsonius]:

THEODORO HARLEMIO PICTORI
Huc et ades, Theodore, tuam quoque Belgica semper
Laude nihil ficta tollet ad astra manum,
Ipsa tuis rerum genitrice expressa figuris
Te Natura sibi dum timet arte parem

Translation of Inscription [Lampsonius]:

To Dirck Bouts, painter 
You are here too, Theodore.  Belgium shall always also raise your hand to the stars with no false praise, while Nature, expressed by your figures, fears you, equal to her in the art of begetting things. ¹

1. I am taking “rerum genetrice” as qualifying “arte” in the next line.  This is awkward, but I cannot see a better solution.