The present invention relates to a method for the manufacture of sheet molding compounds (SMC) in which the required glass fiber nonwovens are manufactured in-line and have an inhomogeneity of 10% or less, a weight per unit area of 400 g/m2 or higher and a strength of less than 10 N. Furthermore, the present invention describes resin mats that comprise the glass fiber nonwovens in accordance with the invention that represent valuable intermediate products.