I made a short video about this art journal here.
I used the Sakura Glaze Gel Pen - White from the JetPens sampler. First time using this pen from Sakura. It took me a few tries to get it to work. To be honest, I thought the pen was deflected until I read the description on JetPens website.
Here is the description from JetPens website:
A favorite for craft and art projects, Sakura Glaze pens feature a unique 3-D ink that leaves a glossy raised line you can see and feel! They can write on regular paper as well as non-porous surfaces like plastic, glass, and metal. Use them on translucent or transparent surfaces to create a stained glass effect.The ink is waterproof on most surfaces, water-based, odorless, and AP certified non-toxic.
For best effect, write slowly to allow a thick line of ink to form and allow the ink to dry completely, which takes up to 10 minutes on most surfaces. Because the ink is thick and slow to dry, it is not ideal for extended writing. The raised effect works best on non-porous, clean, smooth surfaces and can be crushed down by pressing on it.