With normal text in Designer 2, you can change the size either by changing the point size in the text dialog or by dragging the text box handles on the board. With the decorate text along a curve it first seems that one can only change the size using the point size in the text dialog. You will notice, however, that if you pick the text size too large in the dialog, the text size will only increase in size until the text reaches the end of the curve. At this point you can now tweak the size of the text on the board by changing the length of the curve.