The invention includes methods by which the size and shape of photoresist-containing masking compositions can be selectively controlled after development of the photoresist. For instance, photoresist features can be formed over a substrate utilizing a photolithographic process. Subsequently, at least some of the photoresist features can be exposed to actinic radiation to cause release of a substance from the photoresist. A layer of material is formed over the photoresist features and over gaps between the features. The material has a solubility in a solvent which is reduced when the material interacts with the substance released from the photoresist. The solvent is utilized to remove portions of the material which are not sufficiently proximate to the photoresist to receive the substance, selectively relative to portions which are sufficiently proximate to the photoresist. The photoresist features can be exposed to the actinic radiation either before or after forming the layer of material.