If using as kitchen backsplash, is there any product you can use or spray/paint on top to give it a glossy instead of matte finish?

Thank you for your interest in our products! Yes, a sealant or clear coat that can be used on a PVC product can be used to seal our products. Since we have not done any testing, we would recommend contacting the sealant/paint manufacturer for their installation guidelines as well as testing it on a sample prior then putting it on a full installation right away. If you have any additional questions please feel free to reach out to our customer care team at 800.434.3750. Thank you!