良工苦心: a piece of work embodying one's utmost effort; one's bitter toil spent in writing [painting]; expert craftsmanship is the result of long practice and hard work
Example Sentences:
1.
It ' s the result of thirty years ' hard research 这是三十年苦心研究的成果。
2.
I had been struggling with a few concepts for matte paintings for quite a while 有一阵子，我曾苦心研究一些油画等表现肌理的绘画形式。
