Yes, almost always. The rule of thumb is:
Cutaway on knits
Tearaway on wovens.
So for tees and sweats you would typically need a decent tearaway.
IF and only if the fabric is super stable and dense do we run without backing. things like 600D woven poly or a carhartt style jacket...
Now having said that, since you mention applique, if your applique runs a placement stitch, stops and you place an applique that is then sewn down, then you may be able to get away with a light tearaway, just enough to stabilize.
Experiment a little. We keep a fairly standard stock of backings:
1.5 ounce tearaway in 8X8 and 16X22 precuts
2.5 ounce cutaway in the same two precut sizes
Polymesh in a 7X7 precut
Rolls of heavy tearaway for caps
Solvy in 7X7 precuts and rolls
And a couple of specialty backings like the new one for performance fabrics.
We don't cut corners on our supplies, good thread, good backings etc make it a lot easier to be consistent.
Your mileage may vary.
Cutaway on knits
Tearaway on wovens.
So for tees and sweats you would typically need a decent tearaway.
IF and only if the fabric is super stable and dense do we run without backing. things like 600D woven poly or a carhartt style jacket...
Now having said that, since you mention applique, if your applique runs a placement stitch, stops and you place an applique that is then sewn down, then you may be able to get away with a light tearaway, just enough to stabilize.
Experiment a little. We keep a fairly standard stock of backings:
1.5 ounce tearaway in 8X8 and 16X22 precuts
2.5 ounce cutaway in the same two precut sizes
Polymesh in a 7X7 precut
Rolls of heavy tearaway for caps
Solvy in 7X7 precuts and rolls
And a couple of specialty backings like the new one for performance fabrics.
We don't cut corners on our supplies, good thread, good backings etc make it a lot easier to be consistent.
Your mileage may vary.