How can text be so sharp & clear in Xfce4 compared to other desktops and window managers?

How can text be so sharp & clear in Xfce4 compared to other desktops and
window managers?

In the past 1 week i installed different window managers
and desktop environments.
out of these, gnome did not have text as clear and as
sharp as Xfce
but neither did anything else.
text is simply too clear in Xfce4
what is the secret behind this desktop environment ?
is it using special fonts ? or is it using a special setting
to achieve this much precision ?
i want to switch to OpenBox but i am stuck in Xfce due to
clear text , regardless if it is within firefox or outside of
firefox. text is always sharp and clear that it is extremely
easy to read.