Resolene is either the best product for finishing leather, or the worst, depending on who you ask. I personally have experienced both amazing results and terrible ones. If you wipe it on at 100% strength it will not flatten when it dries and leave you with a streaky mess. A 50/50 or 60/40 mix will allow the product to flow evenly over the leather and dry to a flat film giving you a smooth glossy surface. Use light coats and don't fuss with it until it is dry. Resolene really shines when it sprayed on. I use an small hvlp spray gun.
Be sure to do a test piece. I have had experienced an "oil and water" reaction when I applied it over Fieblings Low VOC dye and even spraying it on I got splotchy coverage.