How long did you leave them under the paper towel? i had 15 big bud & widow seeds i threw in a paper towel and put in the water cupboard, i had 2 inch roots on every one of them 18 hours later, after 48 hours and a transplant i had my second sets of jaggered edged leaves appearing, i couldn't get over how fast the shit was growing! on a bad note my timer failed so the poor things fried in there 5th day.

some strains are different and take alot more effort for germination, you want to place some plastic wrap over your put and put it near a lamp e.t.c just to create some humidity, seeds/baby's love this!