The most common and most likely answer to this crossword clue is the 8 letter word TOILSOME
T
O
I
L
S
O
M
E
More clues leading to the result TOILSOME
- Paintings to appear in learned book perhaps that's hard work
- Inserting paintings into book is laborious
- Pictures in large book needing effort
- Needing much effort to place paintings in book
- Hard work gets paintings into book
- Insertion of paintings into book is involving hard work
- Arduous book about painting
- Long book about artists’ materials is hard going
- Punishing when you work a little
- Difficult medium for painting in volume
Buddy explains!

The straight part
We know that "Punishing" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case punishing = toilsome.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 TOILSOME mean?
TOILSOME adjective- Requiring continuous physical effort; laborious.