Students at the Black Mountain School are poised to enhance the royal look on April 24, when they present a silk tie and scarf to William and Kate during the royal couple's visit to the national arboretum.

Rebecca, 19, helped make the pieces during art classes, and she, along with fellow pupil Kirby, 18, have been chosen to meet the Duke and Duchess.

Rebecca's mother presented flowers to the Queen during a previous royal visit, and Kirby was selected for the task due to her excitement and enthusiasm for the Duke and Duchess.

The silk accessories are extremely popular in Canberra and had to be withdrawn from sale at a local gallery because the demand for them had became too strong for the students to fill orders.

The pieces are limited edition marble-dyed screen-printed silk, made by the students through an industrial art program.

The tie for Prince William has an illustration of Black Mountain Tower and the scarf for the Duchess of Cambridge has delicate tassels.

''We did a tower series and we thought the Duke of Cambridge would like something that has a unique Canberra feel,'' school principal Frank Fogliati said. ''The students have been making silk products for a number of years, and we wanted to give something special that was made for the centenary year and which is limited edition.''

The school has sold some of its creations at the Hall Markets and still sells silk pieces from the school office.

The Duke and Duchess will plant an English oak during their visit to the arboretum. The tree is known for its long life, with some specimens recorded as growing for more than 1000 years.

The Duke and Duchess will plant in a young two-metre tree, which will have the potential for a branch span of 20 metres when it is fully grown, casting welcome shade over the arboretum's pod playground.