Fashion illustration is fast becoming the latest party trick, with sketches replacing selfies at major events including the Sydney spring racing carnival.

Illustrator Natalie Rompotis, whose drawings have been reposted by actress Reece Witherspoon and shared on Beyonce's website, says the skill is in popular demand at the races.

"There has been a real renaissance with fashion illustrating. It is going through a bit of a rebirth and is very very popular," she told AAP.

"It is a different point of interest and adds another element to fashion at the races."

Racegoers are quickly snapped by a photographer before Ms Rompotis spends 15 to 20 minutes sketching.

"I have seen some amazing and gorgeous outfits and it just gives us pleasure to be able to draw them," she said.

On any given race day, Ms Rompotis and fellow spring carnival fashion illustrator Alexandra Nea, can draw between 40 and 50 sketches - each of which are presented to their respective models before the end of the race meeting.

"It is lots of fun and people love to see that someone has gone to so much effort to capture their outfit," she said.

"It is really lovely and nice to hand something to someone at the end of the day - and a lot of the time they frame them."

"I guess because this is an everyday thing you don't appreciate your own and I have never had a negative reaction. Maybe they are being polite I don't know!"

Ms Rompotis said while she has only been employed as an illustrator in recent years, the demand for the artful skill has been on the rise within the fashion industry.

"I find now because there is such a focus on photos and social media it is a different element to bring and it is as far as your imagination can take you so we can add a bit more drama to it."