Just to add to Nikki's reply. You need to give it some thought beforehand. When the letters are converted to curve, they are Bezier, which is fine because Bezier can handle tight corners. Splines cannot unless one manually adds a knot. Therefore if using something like Times font, the 'T' would droop. All the straight lines would end up curved by TC to maintain continuity.
If doing manually (and TC pro) using Times, one would draw the polylines and splines separately and use compound profile option if converting to 3D. Or add extra spline nodes at corners to get them as tight as possible. TC when converting from Bezier to spline will not do this.
Obviously, letters with a hole in them, a, b, d etc. may require exploding to two separate polylines. before converting to curve.