Alpaca have "great eyesight" and are very inquisitive animals, according to Mr Medcraft's 9-year-old daughter Rachel.
"They are loveable," she said.
"They are terrific with kids," her father said.
The fleece fetches from $10 to $12 per kilogram and comes in many natural colours ranging from white through to browns and black, Mr Medcraft said.
"It's a beautiful fleece which comes in 25 different natural colours. It is a mid-20 micron fleece," he said.
During Sunday's open day there will be displays with products on sale and spinners on site to show how the wool is spun.
Mr Medcraft's property and one in Carterton will be open from 11am to 4pm. Please phone to confirm if it is raining.