Answered by Shaykh Abdul-Karim Yahya, SunniPath Academy Teacher
Some leather socks (khuffain) have gold printing showing the manufacturers logo etc. on the side of them. Therefore is it permissible to wipe over the area where it is printed and the wiping still be valid? Secondly, most have either a zip, or a button with a flap and a zip. Is it permissible to wipe over these and the wiping still be valid? Also is the answer you give for all schools or just ours?
In The Name of Allah, Most Merciful and Compassionate
In the Shafi’i School it is sufficient to wipe some portion of the khuff that is over the top of the part of the foot which is obligatory to wash in ablution. Wiping the bottom, heel, or sides of the khuff is not valid. 
Wiping over printing, a zipper, button, or flap is valid if these things are in the area that must be wiped. The color of printing on a khuff does not harm the validity of prayer. And Allah knows best and He alone gives success (tawfiq).
 See: Ibn Hajar al-Haytami, Hawashi al-Sharwani Wa Ibn Qasim al-Abbadi ‘Ala Tuhfah al-Muhtaj Bisharh al-Minhaj (Beruit, Dar Ihya’ al-Turath al-‘Arabi), 1:254-255.