I had the same problem when I tried to stain (actually, dye) the cabriole legs I had made for a chair. Luckily I had a practice piece I'd started with and discovered the problem before I got to the final pieces. Jeff Jewitt suggested I give the pieces a coat of Fuhr's #155 prior to the dye. It is water white and very thin. After it has dried go over the piece with sand paper very lightly. Don't worry about loss of detail; you're not sanding that hard. In the endgrain the Fuhr's has penetrated deeply very little is on the surface. On the face grain there has been very little penetration. The Fuhrs sands off easily. When you go back with the dye or stain the penetration is much more even. I think I've heard you can do the same with a very dilute shellac, but the thing about this material is it sands so easily on the long grain and penetrates so deeply on the end grain. You can get it at Homestead Finishing as well as other places, but I can't say where. Good luck.