Rinse cucumbers, trim ends, and slice ¼ inch thick.
Add cucumbers, onions, and salt to a bowl. Cover with a towel and ice. Chill 4 hours.
Rinse and drain well.
Heat jars in boiling water bath if canning.
Combine vinegars, sugar, and spices in pot. Bring to a boil.
Add cucumbers and onions. Boil again.
Pack hot jars with pickles and syrup.
Seal jars and process 15 minutes in boiling water bath.
Cool and store. Refrigerate if not sealed.
