The most common and most likely answer to this crossword clue is the 7 letter word MACRAME
I've seen this crossword clue in Financial Times
M
A
C
R
A
M
E
More clues leading to the result MACRAME
- Ropy work, in which arm came loose
- Staff transporting stuff for ornamental work
- Securing male, staff tying string
- Fabric items, manufactured stuff for Germany
- Ropy work from staff packaging butter
- West hoarding stuff, a knotty art
- Frenchwoman taking credit for daughter’s handiwork
- Ornamental work showing sheep in club
- Fringe stuff seen in West?
- Staff holding stuff to be ropy work
Buddy explains!

The straight part
We know that "a knotty art" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case a knotty art = macrame.The cryptic/wordplay part
In cryptic crossword there's often an wordplay/cryptic part as well.This part involves a more complex hint, such as an anagram, homophone, hidden word, etc.
Sadly, We don't have an explanation for this specific crossword clue yet.
What does MACRAME mean?
MACRAME noun- A form of decorative textile made by knotting and weaving.
- To create textiles using the macramé technique.