kabin ni etsuke o suru.

I paint a design on the flower vase.

Breakdown of kabin ni etsuke o suru.

• を: direct object particle
• する: to do
• に: target particle
• 絵付えつけ: painting a design on pottery

Questions & Answers about kabin ni etsuke o suru.

How do you read 花瓶に絵付けをする?

It is read:

かびん に えつけ を する

Word by word:

• 花瓶（かびん） = vase
• に = on / onto / to
• 絵付け（えつけ） = decorative painting; applying a painted design
• をする = to do

Also, in normal Japanese writing, this would usually be written without spaces:

花瓶に絵付けをする。

What does に mean here?

Here, に marks the target or surface that receives the action.

So 花瓶に絵付けをする means something like:

• do decorative painting on a vase
• apply a design to a vase

The vase is not the direct object of する. Instead, it is the thing the decoration is being applied to.

Why is it 絵付けをする instead of making 花瓶 the object with を?