On Fri, 28 Dec 2007 10:01:36 -0800 (PST), Mikepier
wrote:

I think my problem is I'm using the round "surface mount" spacers they
sell at Lowe's, like these
http://www.tile-eze.com/0310.html,
not the "x" shaped spacers that you can put underneath the tile like
these
http://hand-tools.hardwarestore.com/...e-spacers.aspx
The back of the tile looks a little more uniform than the front so
perhaps I should use the latter type of spacer

Well, I've learned my 'lesson for the day'. I'll have to go check
the jobs I did 30 years ago- but my last tile job in this house was 20
yrs ago and the spacers I never removed have remained hidden in the
grout. Never knew they were supposed to be removed.

Jim
[and doubt I'll remove them next time- if there is a next time]