Make sure the graphics card is fully Windows 95 compatible.
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Check that the card supports the screen resolutions and number of colours you need (1024 x 768 in 256 colours for general home/office use; 16 million colours for graphics and image editing).
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For serious graphics, you will need a card with 2Mb or more of video Ram 'on-board'.
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VRam cards are better than DRam cards, but cost more.