Thank you for that information.
You have probably already seen this Wikipedia description; but just in case, I will include it here.
"Thomas Landseer (1793 or 1794– 20 January 1880) was an artist best known for his engravings and etchings, particularly those of paintings by his youngest brother Edwin Landseer.
Landseer was born in London, the eldest of the fourteen children of engraver John Landseer. Seven of the children survived to adulthood and all became artists; his younger brothers were painters and later Royal Academicians Charles Landseer and Edwin Landseer. Like his father, Thomas was deaf. He was the only sibling to marry, his wife's name was Belinda. His son George Landseer became a portrait and landscape painter.
Like his siblings, Landseer was taught artistic techniques by his father. He then studied under painter Benjamin Robert Haydon alongside his brother Charles and William Bewick. He began etching aged 14, copying his precocious brother's drawings. Thomas continued to make etched copies of Edwin's works in later life, including Dignity and Impudence (1841), Alexander and Diogenes (1852), The Monarch of the Glen (1852) and, his last work, The Font (1875). His soft-ground etchings complimented his brother's animal paintings, and sales of the popular prints (retailing for between 3 and 10 guineas) contributed to his brother's fame and fortune. He assisted his brother with giving art lessons to Queen Victoria and Prince Albert.
Landseer produced satirical etchings of monkeys in human clothing for Monkeyana, or, Men in Miniature (1827), and dedicated his Characteristic Sketches of Animals (1832) to the Zoological Society. He also produced illustrations for ***** ***** Coleridge's Devil's Walk (1831). He also exhibited paintings at the British Institution and the Royal Academy. He was elected an associate of the Royal Academy in 1867 for his etchings. He edited a biography of William Bewick published in 1871.
He died at 11 Grove End Road, St. John’s Wood, on 20 January 1880. He was buried at Highgate Cemetery."
When assessing an artist's work, appraisers must look at sales of works by the same artist. Art gallery sales prices are private.
We must then go to auction sales prices which are public. When using comparable work by the same artist, medium, subject matter and size are factors to be considered.
Appraisers most often use price per square inch of previously sold comparable works by the same artist as a measure of value.
Using this standard method, I was able to determine an estimated auction value of your engraving, which is rather large for Landseer, to be $1813.
A retail art gallery would charge an estimated $4000-4500 for your large engraving with its poem. Please understand that retail art gallery prices depend on the tastes of the gallery owner and the location of the gallery.
A private seller to a dealer or at auction can expect 30-60% of retail value.
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