I apply with a foam roller. Apply generously and roll out the ridges at the edges of the roller with ever lighter pressure until only the weight of the roller is working. This gives me great results. I get no underlying patterns from drips while moving the roller across untreated canvas, as I did with another brand.

We have a lot of photo canvas prints on our walls---often receiving sunlight and this coating seems to protect them from the UV light.

Have noticed a lot less fading on the ones we treated. Super easy to use.

This varnish is top quality. The satin finish is a good compromise between matte and glossy. I was amazed by how carefuly and securely the varnish bottle was wrapped and shipped.

I have learned that ink jet-printed canvases absolutely must be protected with a varnish layer if one expects them to last, especially through the rigors of displaying at art fairs or transporting to and from my gallery. Further, just handling the printed canvas when stretching causes smuging, especially with dark or black ink areas. Additionally, a coating of varnish makes the print "pop" with contrast, vibrancy, and sheen.
So, I tried of the "leading brands" of varnish on my fine art photographic ink jet cavas wraps (printed with OEM pigment inks on my Canon Pro-4100). Though sometimes usable, these two brands of varnish did not spray well. I would end up getting runs quite easily or these strange little raised white bumps would appear in places on the surface while curing/drying. Picking the tiny bumps off with my fingernail would then leave a small dot with no bump, but also, now no ink! Aghhhh! So, I swithched to using a foam roller, with mixed results. I find it very hard, even with a lot of experience and exacting technique, to not leave some roller marks.
Then... I heard about and read some reviews for Breathing Color Timeless Varnish and thought I'd give their satin finish product a try. Though it is still hard for me to get perfect results with a foam roller, the product does seem to have excellent self-leveling properties that help with that a lot. And foamy air bubbles are not as present with Timeless as with the other two products when applying with a foam roller. THEN... I thought I'd give spraying another try with the Timeless Varnish and wow! I never plan to use a roller again! This stuff is fantastic!
Applying two or three light coats, moving quickly with my inexpensive HVLP sprayer, yields a superb result for me. The finish is durable, clear, neutral, stretcable, and professional looking. My only issue is not a problem with the product but is due probably to my cheap sprayer and my not paying attention. I can get some small glops of varnish if the sprayer sputters when it begins to run out of product. However, if I notice these spots immediately, while still wet, I can dab these with my fingertip to remove. Then, because of the product's superb self-leveling properties, any smudge left from my finger usually just disappears. If it doesn't disappear completely, another coat of varnish will mitigate that. Considering that the other two products I tried cost about twice as much as Timeless Varnish by Breathing Color, I am very thrilled to have found this product! I'm hooked!
-Kenneth Keifer Photography

Timeless Print Varnish is a high quality protective water soluble solvent that rolls on easily and is rated to last for many years.