Haven't used number tags on blocks for over 25 years. 

Modern technology has all but eliminated the need to use tags embedded into
the paraffin.  Consider switching to tissue cassettes that can be directly
labelled (either with pencil, special ink pins, or automated cassette
labellers). It is very time and cost effective.  Cassettes are then held in
special block holder in microtome, and filed in cabinets so you can read
acc numbers and retrieve blocks instantaneously.  

There are whole cassette systems from start to finish (in block holder for
these cassettes) put out by many vendors.   

 At 09:28 AM 1/12/01 -0800, you wrote:
>I am curious to find out if there are many people out there who are
>using the number tags to put the accession number on blocks.  We are
>using them here, and we find them a real pain.  It is harder to embed
>because you have to set the tag in just the right position so that it
>doesn't sink into the melted paraffin in the block.  Often, the paraffin
>build-up where the tag sits on the edge of the cassette edge is too
>thick, so that when we go to cut the block it will not fit into the
>block holder properly.  Then we either have to sit the block on our hot
>plate to melt the paraffin or cut the very edges of the tags.  It is
>also a pain to file and retrieve blocks because you cannot see the
>number.
>
>We are going to experiment with putting the tag on the area of the block
>where you write the number, but I am afraid the tags are going to fall
>off.
>
>I would appreciate any ideas, suggestions, and/or comments from others
>who are using the tags.
>
>Laurie Colbert
>Huntington Memorial Hospital
>Pasadena, CA
>
>
>
>
Gayle Callis
Veterinary Molecular Biology
Montana State University
Bozeman MT 59717-3610
406 994-4705
406 994-4303