Constitution, conformation and bulk of fleece is an old adage which George and Helen McKenzie adhere to in their Montrose Hill breeding program with great results.
"My focus has always been about filling wool packs," Mr McKenzie said.
"Sheep have got to have thrift, they have to be able to reproduce and they have to produce the largest volume of wool in that micron category.
"I believe wool cut is absolutely paramount and it doesn't matter if you are breeding ultrafine or strong wool sheep."
Last year, a six-tooth ultrafine ewe bred by the Illabrook-based stud was named the supreme exhibit from 853 Merino and Poll Merino sheep at the Australian Sheep & Wool Show (ASWS) in Bendigo.
The ultrafine judge, James Collins, Mt Bute stud, Linton, said he couldn't fault her.
"Her wool was sweet from the head to the tail, and the underneath was as good as it was on top; she is a structurally perfect sheep," Mr Collins said.
With impressive fleece measurements of 15.5 micron, 2.7 standard deviation and a comfort factor of 99.7 per cent, 'Rosie' is by a Montrose Hill-bred sire (032), who was sashed champion superfine ram at Bendigo two years ago.
According to Mr McKenzie, taking home the coveted supreme exhibit was "the thrill of a lifetime" and the biggest win in the 34-year history of their stud.
"We have had some very good ewes over the years but Rosie stood out from day one," he said.
The McKenzies' planned to take 'Rosie', who was heavy in lamb with twins, to the Dubbo National, NSW, in August last year, but unfortunately she fell ill and lost her lambs.
After her recovery, the champion ewe was successfully flushed in an embryo transfer program in April producing 19 fertilised embryos.
Mr McKenzie is looking forward to seeing her lambs, who have been sired by a home-bred ram, hit the ground at the end of August.
The Montrose Hill stud currently runs 900 stud Merino and Poll Merino ewes as well as a self-replacing commercial flock of 1200 ewes.
The long-term average micron across both flocks is 17.5.
"I have introduced sheep within our type to improve specific traits such as staple length and wool cut and size is also important," Mr McKenzie said.
"But people can get caught up with size and in a commercial operation a big sheep can use a lot of feed to produce not much, it's a matter of getting the balance right."
Montrose Hill have entered a show team of eight young ewes and rams for Bendigo this year.
"I believe it is the shop window of the sheep industry."