Inserting a PICT file into a Paint document and saving will result in a file which is larger than the original PICT file. Copying and pasting from a draw document to a paint document will have a similar result.
PICT is object oriented whereas the Paint environment saves in bitmaps. Likewise, ClarisWorks drawing files are object oriented. Object oriented files can store the description of each object in the file using very little RAM or disk space. Conversely, bitmap environments, like ClarisWorks Paint files, store every dot (pixel) of information. Thus, PICT and ClarisWorks draw files are usually smaller, since it takes less memory to store the description of say, a square, than it takes to store all the dots in a bitmap that look like a square.
Workaround:
The Paint environment allows you to change the resolution and bit depth of a document or frame. Standard settings are 72 dpi and pixel depth of 256. If your painting contains fewer colors, then change the pixel depth accordingly. For example: a black and white painting saved as 72 dpi and 256 depth was 305k, resaved as 72 dpi and Black & White depth was 40k.