Seat cushions should be soft and comfortable, and should give a little, but not too much for most users. For our traditional polyurethan foam, start with our medium V44 Everflex foam for cushions between 4 and 6 inches thick. For organic seat cushions, We offer two main types of foam for indoor seat cushions; our traditional polyurethane (free of harmful chemicals), and our organic latex foam. Starting with the traditional polyurethane, we recommend our Everflex foam for couch cushions that will be used most days, and our lower-cost Econoflex foam for occasional use couch cushions in guest rooms or seldom-used areas. Most customers will be happy with our medium-firm V44 Everflex foam for couch cushions between 4 and 6 inches. If your couch cushion is thinner, you might consider firmer V54, and if thicker than 6 inches we generally recommend our softer V34. For latex foam, we recommend medium N31 or medium-firm N36 for standard thickness cushions. You can also select cushions using memory foam as a top layer above firmer polyurethane foam. Contact our customer service team for help with ordering.