The problem consists in taking two polyominoes, say a tetromino and a pentamino, and finding a figure which can be tessellated indipendently by both the polyominoes. Like these:

   or  
I discovered and became interested in this problem thanks to the great pages of
Livio Zucca (and in particular Page1, Page2, and Page3) and of Jorge Luis Mireles which collect a large number of results, mostly obtained by hand by a small group of polyomino "heroes".

I can't solve these problems by hand. (I have difficulties even in telling if two polyominoes are the same apart reflection and rotation...), so I wrote a little program that searches solutions for me, since I like to look at them.
In the following pages I collect the results I obtained running my little program.

I must point out that a large fraction of the solutions I report here has been probably already obtained by other people. I apologize for this, but I'm not really interested in the game of I did it before you did, nor I have the time to compare all the solutions and attribute ownership. I will do it only in the few cases in which the computer program does not find an already known solution.

I also apologize for the names of the polyominoes. I did most of the work during the Christmas holidays, when I was out of Internet, so I did not have a model to conform to. After that, I was too lazy to change all the names...
A list of the polyominoes I have used is here.

The Pdf documents, in universal page format, are there to help (I hope) the printing.
 

 Pairs Web pages Pdf documents Solved
Pentomino - Tetromino tetrominoes tetrominoes (20Kb) 58 / 60
Pentomino - Pentomino pentominoes pentominoes (12Kb) 60 / 66
Hexomino - Tromino trominoes IL trominoes IL (13Kb) 70 / 70 
Hexomino - Tetromino tetrominoes tetrominoes (44Kb) 166 / 175
Hexomino - Pentomino pentominoes pentominoes (136Kb) 389 / 420
Hexomino - Hexomino hexominoes hexominoes (94)k 550 / 595
Heptomino - Tromino trominoes IL trominoes IL (58Kb) 216 / 216
Heptomino - Tetromino tetrominoes tetrominoes (161Kb) 473 / 540
Heptomino - Pentomino Pentominoes FILN
Pentominoes PTUV
Pentominoes WXYZ
Pentominoes FILN (104Kb)
Pentominoes PTUV (151Kb)
Pentominoes WXYZ (106Kb)
1100 / 1296
Octomino - Tromino tromino I
tromino L
tromino I (108Kb)
tromino L (97Kb)
734 / 738
Octomino - Tetromino tetromino I
tetromino L
tetromino N
tetromino Q
tetromino T
tetromino I (68Kb)
tetromino L (28Kb)
tetromino N (63Kb)
tetromino Q (48Kb)
tetromino T (60Kb)
308 / 369
369 / 369
360 / 369
144 / 369
361 / 369
Octomino - Pentomino pentominoes    
Enneomino - Tetromino tetromino I
tetromino Q
   
Dekamino - Tetromino tetromino L