Originally Posted by 3alarmer

...it's a contact cement, so spray onto both surfaces and let dry before attaching the saddle covering.

You will probably have some issues with overspray, until you've done a few saddles and get the knack of masking.
Keep a rag with mineral spirits handy. You need to remove anything that is not under the covering.

I've done 30 or 40 saddles with this stuff, and they are all holding up fine in use.