Hi all, I'm a printing-n00b; only done 15 so far. Have used grades 1, 2 and 2.5, no dodging or burning yet. What I'd like to know is, how much variation in contrast & sensitivity can I expect between two packs of the same paper type, most likely an Ilford MGIV pearl (44m)? Reason being, I'd like to do test strips and a few whole test prints in varying contrast at 5x7 before laying down a 12x16 or larger. Can I compute a time ratio based on the area ratio of the enlargements or will I get bitten by sensitivity differences or reciprocity failure in the paper? Assuming I run a test strip to get a new exposure for the larger size, can I assume the contrast will be the same? In other words, can I get away with 0 or 1 test strips from the larger pack after doing all my experimenting with the smaller pack? thanks.