Harsimrat Kaur @HarsimratBadal_says "our Gurus saved your Tilak"
She is wrong. There was no "us versus them" when it came to Tilak . Sikh Gurus themselves wore Tilak. This can be seen in most of the old Sikh paintings.
Here is a thread
Here is an old Sikh painting of Guru Nanak (seated in the middle) along with Bhai Bala and Bhai Mardana.
His Tilak on the forehead can clearly be seen.There is a Rudraksha Mala in his hand. Notice his ears are also pierced.
Illustration from Janamsakhi. Sikh painting (c. 1800)
Here is another painting. Guru Nanak (centre) is clearly shown with a Tilak and Seli Topi.
Guru Nanak meeting Sheikh Sharf. Illustration from Janamsakhi. Early Sikh painting (c.1700)
Here is another depiction of Guru Nanak (second from left) from the 300 year old Baba Ram Rai Darbar.
Again, his Tilak is very noticeable.
Here is another painting of Guru Nanak(seated in the middle) with Bhai Bala and Bhai Mardana. His Tilak and Vaishnav Seli Topi can clearly be seen.
Another illustration of Guru Nanak with Chandan Tilak, Mala and Vaishnav Seli Topi.
Here is another painting of Guru Nanak with his son Sri Chand. This painting is from Dera Baba Nanak Gurudwara which was setup by the descendants of the Guru
Here is a personal collection of Guru Nanak's Seli Topi, Rudraksha, Shaligram and his handwritten copy(pothi) preserved by descendants of Guru Amar Das who had set up their headquarters in Guru Har Sahai (Punjab) .
Here are a few paintings of Guru Tegh Bahadur himself with a Tilak. The second painting is housed in Lahore Museum (Acc. No. F-47)
Until 1900, paintings of Sikh Gurus typically show them with a Tilak. Even if the Chandan Tilak is sometimes hardly visible in paintings.
In modern Sikh paintings, however, they are not depicted with a Tilak. Here is an example
An illustration of Baba Budha anointing Guru Arjan Dev with Tilak. Frequently depicted in historic Gurudwaras. Guru Ramdas tilak anointment is mentioned even in Guru Granth Sahib.
ਰਾਮਦਾਸ ਸੋਢੀ ਤਿਲਕੁ ਦੀਆ ਗੁਰ ਸਬਦੁ ਸਚੁ ਨੀਸਾਣੁ ਜੀ
The Guru then blessed Sodhi Ram Das with Tilak