These bags aren't heavy. They are light bags.

这些包不重，它们是轻的包。

youdao

The doctor advised that he should change the heavy shoes for light ones.

医生建议他把重的鞋换成轻的鞋。

youdao

We used to mistake that heavy objects fell faster than light ones.

我们过去错误地认为重的物体比轻的物体下落更快。

youdao

Thick walls are extremely heavy, and allow less room for windows and light.

VOA: special.2010.03.31

At the bottom of the light house was big heavy rocks.

VOA: special.2010.05.08

Batteries are bulky and heavy, and for machines that need to be light.

VOA: standard.2010.08.11

The military intercepted a ship in the Mediterranean Sea and found heavy and light weapons aboard, Lebanon's National News Agency reported.

CNN: STORY HIGHLIGHTS

Obviously, your tone is going to matter a lot here: you can make the delivery as heavy or light as the situation warrants.

FORBES: Woman Interruptus: Interrupting Is Not A Form Of Encouragement

Low demand during 2011 was caused by high rare earths prices from both heavy and light rare earths metals, which despite their fluttering prices, remain historically high.

FORBES: 2012 Outlook: Uncertainty Continues For Rare Earths Prices, China Still Major Player