Considering the difficulty in making metal plates, it was critical to conserve space on the Nephite records. Writing in Egyptian hieroglyphs rather than in their native Hebrew allowed the writers to occupy less space. Moroni wrote;

"We have written this record according to our knowledge, in the characters which are called among us the reformed Egyptian, being handed down and altered by us, according to our manner of speech. And if our plates had been sufficiently large we should have written in Hebrew."

Demotic Egyptian was phonetic, each character representing a unit of speech, therefore, there would have been no substantial space saving over writing in Hebrew. The Nephite prophets would have taken up more space on the plates writing in demotic characters than writing in their native Hebrew. This can easily be illustrated with the Rosetta Stone.

The Rosetta Stone is a fascinating artifact that continues to amaze archaeologists and laypeople alike. Carved in 196 B.C., it contains an engraving written in two languages, Egyptian and Greek. It was discovered by Napoleon's troops in 1799 after years of being buried deep beneath the sand of an ancient city near the Nile Delta. The most remarkable thing about this stone is not just its age, but also the fact that it contains two distinct inscriptions: one written in hieroglyphs, the other in Ancient Greek. Hieroglyphs were used mainly by priests and those with access to writing materials. Thus, it is truly remarkable that these two disparate idioms are presented side-by-side on this single tablet; a testament to its historical significance as well as its cultural importance.

While the Rosetta Stone is known for its impact on the world of translation, its story begins long before scholars began deciphering it in order to learn about hieroglyphics. It is believed that the stone was first written in demotic Egyptian, followed by a re-writing of certain words and phrases into hieroglyphics. The Greek translations were added afterwards as a way to further explain the ancient messages inscribed onto the stone. 

A rough idea of the possible amount of space saved from Greek to demotic and from demotic to hieroglyphics can be determined by studying the number of characters and the amount of space used for each of these three scripts.

The demotic inscription comprises 23% less space than the Greek inscription. The text contains 54 lines of Greek writing and only 32 lines of demotic. The demotic text contains approximately 3360 characters. The Greek text contains about 6700 characters. The compression of demotic over Greek is about two to one.

Part of the hieroglyphic inscription on the Rosetta stone has been broken off, leaving only 14 lines of hieroglyphs intact. These 14 lines match the last 18 lines of the demotic writing and the last 28 lines of the Greek. The height of the hieroglyphs is about twice that of the demotic and three times that of the Greek characters.

If the hieroglyphs on the Rosetta were equal in size to the demotic, the text would have been half the size that it was. Then only seven lines of hieroglyphs would have corresponded to 18 lines of demotic. Consequently, in order to conserve the necessary space, the Book of Mormon authors must have used highly pictographic, rather than phonetic, Egyptian writing.

Learn more about the coming forth of the Book Of Mormon in Bill Wylson's Hieroglyphs, Golden Plates and Typos.