I have 4 tables that my HB puts up for me either on the patio or in the garage and they are not all the same height so we put something under the legs to adjust that. Then I tape the the back down the best I can and use spray baste or glue and put it all together that way. Some times the back still gets some ripples in it and I turn it over and try to smooth it out. This is the part of quilting I don't care for.