How many tbsp lye = 1 oz?
How many tbsp lye = 1 oz? heaping or flat?
Lye should never be measured by dry measures. Unfortunately it is far to inaccurate and could easily result in lye heavy soap.
Remember that lye is a caustic substance and accuracy is a must. Weighing in grams is the most accurate way to measure lye and is the method that I recommend.
For small batch soap making you can get an inexpensive digital scale from most department stores. They start at around $20 or so.